This issue is related to #3107
This is a first renaming/refactoring step before reworking and removing heartbeats.
As discussed with @Liamsi , we preferred to go for a couple of independent and separate PRs to simplify review work.

The changes:

    Help to clarify the relation between the validator and remote signer endpoints
    Differentiate between timeouts and deadlines
    Prepare to encapsulate networking related code behind RemoteSigner in the next PR

My intention is to separate and encapsulate the "network related" code from the actual signer.

SignerRemote ---(uses/contains)--> SignerValidatorEndpoint <--(connects to)--> SignerServiceEndpoint ---> SignerService (future.. not here yet but would like to decouple too)

All reconnection/heartbeat/whatever code goes in the endpoints. Signer[Remote/Service] do not need to know about that.

I agree Endpoint may not be the perfect name. I tried to find something "Go-ish" enough. It is a common name in go-kit, kubernetes, etc.

Right now:
SignerValidatorEndpoint:

    handles the listener
    contains SignerRemote
    Implements the PrivValidator interface
    connects and sets a connection object in a contained SignerRemote
    delegates PrivValidator some calls to SignerRemote which in turn uses the conn object that was set externally

SignerRemote:

    Implements the PrivValidator interface
    read/writes from a connection object directly
    handles heartbeats

SignerServiceEndpoint:

    Does most things in a single place
    delegates to a PrivValidator IIRC.

* cleanup

* Refactoring step 1

* Refactoring step 2

* move messages to another file

* mark for future work / next steps

* mark deprecated classes in docs

* Fix linter problems

* additional linter fixes

* changelog: use issue number instead of PR number

* follow up to #3291

- rpc/test/helpers.go add StopTendermint(node) func
- remove ensureDir(filepath.Dir(walFile), 0700)
- mempool/mempool_test.go add type cleanupFunc func()

* cmd/show_validator: wrap err to make it more clear

Don't add committed evidence to evpool

As per conversation here: https://github.com/tendermint/tendermint/pull/3218#discussion_r251364041

This is the result of running the following code on the repo:

```bash
find . -name '*.go' | grep -v 'vendor/' | xargs -n 1 goimports -w
```

so if we did not index the last block (because of panic or smth else), we index it during replay

Closes #3186

* add "chain_id" label for all metrics

Refs #3082

* fix labels extraction

https://github.com/tendermint/tendermint/pull/2923#pullrequestreview-192065694

* Close and recreate a RemoteSigner on err

* Update changelog

* Address Anton's comments / suggestions:

 - update changelog
 - restart TCPVal
 - shut down on `ErrUnexpectedResponse`

* re-init remote signer client with fresh connection if Ping fails

- add/update TODOs in secret connection
- rename tcp.go -> tcp_client.go, same with ipc to clarify their purpose

* account for `conn returned by waitConnection can be `nil`

- also add TODO about RemoteSigner conn field

* Tests for retrying: IPC / TCP

 - shorter info log on success
 - set conn and use it in tests to close conn

* Tests for retrying: IPC / TCP

 - shorter info log on success
 - set conn and use it in tests to close conn
 - add rwmutex for conn field in IPC

* comments and doc.go

* fix ipc tests. fixes #2677

* use constants for tests

* cleanup some error statements

* fixes #2784, race in tests

* remove print statement

* minor fixes from review

* update comment on sts spec

* cosmetics

* p2p/conn: add failing tests

* p2p/conn: make SecretConnection thread safe

* changelog

* IPCVal signer refactor

- use a .reset() method
- don't use embedded RemoteSignerClient
- guard RemoteSignerClient with mutex
- drop the .conn
- expose Close() on RemoteSignerClient

* apply IPCVal refactor to TCPVal

* remove mtx from RemoteSignerClient

* consolidate IPCVal and TCPVal, fixes #3104

- done in tcp_client.go
- now called SocketVal
- takes a listener in the constructor
- make tcpListener and unixListener contain all the differences

* delete ipc files

* introduce unix and tcp dialer for RemoteSigner

* rename files

- drop tcp_ prefix
- rename priv_validator.go to file.go

* bring back listener options

* fix node

* fix priv_val_server

* fix node test

* minor cleanup and comments

privval: remove GetAddress(), memoize pubkey

* split immutable and mutable parts of priv_validator.json

* fix bugs

* minor changes

* retrig test

* delete scripts/wire2amino.go

* fix test

* fixes from review

* privval: remove mtx

* rearrange priv_validator.go

* upgrade path

* write tests for the upgrade

* fix for unsafe_reset_all

* add test

* add reset test

* makeNodeInfo returns error

* version and changelog

* Revert to using defers in addrbook.  ValidateBasic->Validate since it requires DNS

* Update CHANGELOG_PENDING

* node: allow state and code to have diff block versions

* node: pex is a log module

* update ConsensusState#OnStop comment

* consensus: set logger for WAL in tests

* refactor privValidator client code and tests

follow-up on https://github.com/tendermint/tendermint/pull/2866

Ref #2827

(I have since seen #2847 which is a fix for the same issue; this PR has tests and docs too ;) )

* p2p: NewMultiplexTransport takes an MConnConfig

* changelog

* move test func to test file

* Decouple StartHTTP{,AndTLS}Server from Listen()

This should help solve cosmos/cosmos-sdk#2715

* Fix small mistake

* Update StartGRPCServer

* s/rpc/rpcserver/

* Start grpccore.StartGRPCServer in a goroutine

* Reinstate l.Close()

* Fix rpc/lib/test/main.go

* Update code comment

* update changelog and comments

* fix tm-monitor. more comments

* fix amino overhead computation for Tx:

- also count the fieldnum / typ3
- add method to compute overhead per Tx
- slightly clarify comment on MaxAminoOverheadForBlock
- add tests

* fix TestReapMaxBytesMaxGas according to amino overhead

* fix TestMempoolFilters according to amino overhead

* address review comments:

 - add a note about fieldNum = 1
 - add forgotten godoc comment

* fix and use sm.TxPreCheck

* fix test

* remove print statement

* only invoke InitWAL/CloseWAL if WalPath is not empty

Closes #2717

* panic if WAL is not initialized when calling CloseWAL

* add a changelog entry

* use types.NewValidator

* node: set p2p.ProtocolVersion from state, not globals

* abci: update RequestInfo for versions

* abci: update ResponseInfo for versions

* compile fix

* fix test

* software_version -> version

* comment fix

* update spec

* add test

* comments and fix test

* p2p: add protocol Version to NodeInfo

* update node pkg. remove extraneous version files

* update changelog and docs

* fix test

* p2p: Version -> ProtocolVersion; more ValidateBasic and tests

* types: add Version to Header

* abci: add Version to Header

* state: add Version to State

* node: check software and state protocol versions match

* update changelog

* docs/spec: update for versions

* state: more tests

* remove TODOs

* remove empty test

Ref: #2563

I added IPC as an unencrypted alternative to SocketPV.

Besides I fixed the following aspects of SocketPV:

Added locking since we are operating on a single socket
The connection deadline is extended every time a successful packet exchange happens; otherwise the connection would always die permanently x seconds after the connection was established.
Added a ping/heartbeat mechanism to keep the connection alive; native TCP keepalives do not work in this use-case


* Extend the SecureConn socket to extend its deadline
* Add locking & ping/heartbeat packets to SocketPV
* Implement IPC PV and abstract socket signing
* Refactored IPC and SocketPV
* Implement @melekes comments
* Fixes to rebase

* p2p: NodeInfo is an interface

* (squash) fixes from review

* (squash) more fixes from review

* p2p: remove peerConn.HandshakeTimeout

* p2p: NodeInfo is two interfaces. Remove String()

* fixes from review

* remove test code from peer.RemoteIP()

* p2p: remove peer.OriginalAddr(). See #2618

* use a mockPeer in peer_set_test.go

* p2p: fix testNodeInfo naming

* p2p: remove unused var

* remove testRandNodeInfo

* fix linter

* fix retry dialing self

* fix rpc

* Fix termination issues and improve tests

* Improve formatting and tests based on reviewer feedback

* Add additional metrics
Continues addressing https://github.com/cosmos/cosmos-sdk/issues/2169.
* Add nop metrics to fix NPE
* Tweak buckets, code review
* Update buckets
* Update docs with new metrics
* Code review updates

* remove some XXX

* config: remove Mempool.RecheckEmpty

* docs: remove recheck_empty

* Add additional metrics to p2p and consensus
Partially addresses https://github.com/cosmos/cosmos-sdk/issues/2169.
* WIP
* Updates from code review
* Updates from code review
* Add instrumentation namespace to configuration
* Fix test failure
* Updates from code review
* Add quotes
* Add atomic load
* Use storeint64
* Use addInt64 in writePacketMsgTo

* stop node upon receiving SIGTERM or CTRL-Ceven during genesis sleep by setting up interrupt before starting a node

Closes #2434

* call Start, not OnStart when starting a component to avoid:

```
E[09-24|10:13:15.805] Not stopping PubSub -- have not been started yet module=pubsub impl=PubSub
```

being printed on exit

This also refactors the prior mempool to filter to be known as
"precheck filter" and this new filter is called "postcheck filter"

This PR also fixes a bug where the precheck filter previously didn't
account for the amino overhead, which could a maliciously sized tx to
halt blocks from getting any txs in them.

* Move maxGas outside of function definition to avoid race condition
* Type filter funcs and make public
* Use helper method for post check
* Remove superfluous Filter suffix
* Move default pre/post checks into package
* Fix broken references
* Fix typos
* Expand on examples for checks

* follow up to removing some consensus params Refs #2382
* change args type to int64 in state#makeParams
* make valsCount and evidenceCount ints again
* MaxEvidenceBytesPerBlock: include magic number in godoc
* [spec] creating a proposal
* test state#TxFilter
* panic if MaxDataBytes is less than 0
* fixes after review
* use amino#UvarintSize to calculate overhead
0c74291f3b/encoder.go (L85-L90)
* avoid cyclic imports
* you can do better Go, come on
* remove testdouble package

- remove second AminoVersion from
https://github.com/tendermint/tendermint/pull/2426/files#diff-f2fefc7a06ea0d1e0a910196901e50aaR86

Refs #2433

Handshaker was removed from proxy package so it can be called
independently of starting the abci app connections and can return a
result to the caller.

We are swapping the exisiting listener implementation with the newly
introduced Transport and its default implementation MultiplexTransport,
removing a large chunk of old connection setup and handling scattered
over the Peer and Switch code. The Switch requires a Transport now and
handles externally passed Peer filters.

* [rpc] transform /status result.node_info.other into map
* amino does not support maps, duh

Refs #2391

* remove ConsensusParams.TxSize and ConsensusParams.BlockGossip

Refs #2347

* block part size is now fixed

Refs #2347

* use max data size, not max bytes for tx limit

Refs #2347

Fixes #2320

* ReapMaxTxs: return all txs if max is negative

this mirrors ReapMaxBytes behavior

See https://github.com/tendermint/tendermint/pull/2184#discussion_r214439950

* increase MaxAminoOverheadForBlock

tested with:

```
func TestMaxAminoOverheadForBlock(t *testing.T) {

        maxChainID := ""
        for i := 0; i < MaxChainIDLen; i++ {
                maxChainID += "𠜎"
        }

        h := Header{
                ChainID:            maxChainID,
                Height:             10,
                Time:               time.Now().UTC(),
                NumTxs:             100,
                TotalTxs:           200,
                LastBlockID:        makeBlockID(make([]byte, 20), 300, make([]byte, 20)),
                LastCommitHash:     tmhash.Sum([]byte("last_commit_hash")),
                DataHash:           tmhash.Sum([]byte("data_hash")),
                ValidatorsHash:     tmhash.Sum([]byte("validators_hash")),
                NextValidatorsHash: tmhash.Sum([]byte("next_validators_hash")),
                ConsensusHash:      tmhash.Sum([]byte("consensus_hash")),
                AppHash:            tmhash.Sum([]byte("app_hash")),
                LastResultsHash:    tmhash.Sum([]byte("last_results_hash")),
                EvidenceHash:       tmhash.Sum([]byte("evidence_hash")),
                ProposerAddress:    tmhash.Sum([]byte("proposer_address")),
        }
        b := Block{
                Header:     h,
                Data:       Data{Txs: makeTxs(10000, 100)},
                Evidence:   EvidenceData{},
                LastCommit: &Commit{},
        }

        bz, err := cdc.MarshalBinary(b)
        require.NoError(t, err)

        assert.Equal(t, MaxHeaderBytes+MaxAminoOverheadForBlock-2, len(bz)-1000000-20000-1)
}
```

* fix MaxYYY constants calculation

by using math.MaxInt64

See https://github.com/tendermint/tendermint/pull/2184#discussion_r214444244

* pass mempool filter as an option

See https://github.com/tendermint/tendermint/pull/2184#discussion_r214445869

* fixes after Dev's comments

See ADR 020: Limiting txs size inside a block docs/architecture/adr-020-block-size.md

Refs #2035

Fixes #1544

* libs: Remove usage of custom Fmt, in favor of fmt.Sprintf

Closes #2193

* Fix bug that was masked by custom Fmt!

also, make running Prometheus server optional.

Closes #2019

Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.

Ref discussion: https://github.com/tendermint/tendermint/pull/1966

Closes #1956

* Add private peer ID tracking to AddrBook

* Remove private peer tracking/blocking from pex

* debug level msg when we fail to add private address

This reverts commit 58d0c8de89.