* limit number of /subscribe clients and queries per client

Add the following config variables (under [rpc] section):
  * max_subscription_clients
  * max_subscriptions_per_client
  * timeout_broadcast_tx_commit

Fixes #2826

new HTTPClient interface for subscriptions

finalize HTTPClient events interface

remove EventSubscriber

fix data race

```
WARNING: DATA RACE
Read at 0x00c000a36060 by goroutine 129:
  github.com/tendermint/tendermint/rpc/client.(*Local).Subscribe.func1()
      /go/src/github.com/tendermint/tendermint/rpc/client/localclient.go:168 +0x1f0

Previous write at 0x00c000a36060 by goroutine 132:
  github.com/tendermint/tendermint/rpc/client.(*Local).Subscribe()
      /go/src/github.com/tendermint/tendermint/rpc/client/localclient.go:191 +0x4e0
  github.com/tendermint/tendermint/rpc/client.WaitForOneEvent()
      /go/src/github.com/tendermint/tendermint/rpc/client/helpers.go:64 +0x178
  github.com/tendermint/tendermint/rpc/client_test.TestTxEventsSentWithBroadcastTxSync.func1()
      /go/src/github.com/tendermint/tendermint/rpc/client/event_test.go:139 +0x298
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162

Goroutine 129 (running) created at:
  github.com/tendermint/tendermint/rpc/client.(*Local).Subscribe()
      /go/src/github.com/tendermint/tendermint/rpc/client/localclient.go:164 +0x4b7
  github.com/tendermint/tendermint/rpc/client.WaitForOneEvent()
      /go/src/github.com/tendermint/tendermint/rpc/client/helpers.go:64 +0x178
  github.com/tendermint/tendermint/rpc/client_test.TestTxEventsSentWithBroadcastTxSync.func1()
      /go/src/github.com/tendermint/tendermint/rpc/client/event_test.go:139 +0x298
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162

Goroutine 132 (running) created at:
  testing.(*T).Run()
      /usr/local/go/src/testing/testing.go:878 +0x659
  github.com/tendermint/tendermint/rpc/client_test.TestTxEventsSentWithBroadcastTxSync()
      /go/src/github.com/tendermint/tendermint/rpc/client/event_test.go:119 +0x186
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162
==================
```

lite client works (tested manually)

godoc comments

httpclient: do not close the out channel

use TimeoutBroadcastTxCommit

no timeout for unsubscribe

but 1s Local (5s HTTP) timeout for resubscribe

format code

change Subscribe#out cap to 1

and replace config vars with RPCConfig

TimeoutBroadcastTxCommit can't be greater than rpcserver.WriteTimeout

rpc: Context as first parameter to all functions

reformat code

fixes after my own review

fixes after Ethan's review

add test stubs

fix config.toml

* fixes after manual testing

- rpc: do not recommend to use BroadcastTxCommit because it's slow and wastes
Tendermint resources (pubsub)
- rpc: better error in Subscribe and BroadcastTxCommit
- HTTPClient: do not resubscribe if err = ErrAlreadySubscribed

* fixes after Ismail's review

* Update rpc/grpc/grpc_test.go

Co-Authored-By: melekes <anton.kalyaev@gmail.com>

ClevelDB requires closing when WriteBatch is no longer needed, https://godoc.org/github.com/jmhodges/levigo#WriteBatch.Close

Fixes the memory leak in https://github.com/cosmos/cosmos-sdk/issues/3842

ClevelDB requires closing when WriteBatch is no longer needed, https://godoc.org/github.com/jmhodges/levigo#WriteBatch.Close

Fixes the memory leak in https://github.com/cosmos/cosmos-sdk/issues/3842

Refs #3262

This fixes two small bugs:

1) lite/dbprovider: return `ok` instead of true in parse* functions. It's weird that we're ignoring `ok` value before.
2) consensus/state: previously because of the shadowing we almost never output "Error with msg". Now we declare both `added` and `err` in the beginning of the function, so there's no shadowing.

1."abci_query": rpcserver.NewRPCFunc(c.ABCIQuery, "path,data,prove")
"validators": rpcserver.NewRPCFunc(c.Validators, "height"),
the parameters and function do not match, cause index out of range error.
2. the prove of query is forced to be true, while default option is false.
3. fix the wrong key of merkle

* 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

* improve ResetTestRootWithChainID() concurrency safety

Rely on ioutil.TempDir() to create test root directories and ensure
multiple same-chain id test cases can run in parallel.

* Update config/toml.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* clean up test directories after completion

Closes: #1034

* Remove redundant EnsureDir call

* s/PanicSafety()/panic()/s

* Put create dir functionality back in ResetTestRootWithChainID

* Place test directories in OS's tempdir

In modern UNIX and UNIX-like systems /tmp is very often
mounted as tmpfs. This might speed test execution a bit.

* Set 0700 to a const

* rootsDirs -> configRootDirs

* Don't double remove directories

* Avoid global variables

* Fix consensus tests

* Reduce defer stack

* Address review comments

* Try to fix tests

* Update CHANGELOG_PENDING.md

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* Update consensus/common_test.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* Update consensus/common_test.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* types.NewCommit

* use types.NewCommit everywhere

* fix log in unsafe_reset

* memoize height and round in constructor

* notes about deprecating toVote

* bring back memoizeHeightRound

* types: memoize height/round in commit instead of first vote

* types: commit.ValidateBasic in VerifyCommit

* types: new CommitSig alias for Vote

In preparation for reducing the redundancy in Commits, we introduce the
CommitSig as an alias for Vote. This is non-breaking on the protocol,
and minor breaking on the Go API, as Commit now contains a list of
CommitSig instead of Vote.

* remove dependence on ToVote

* update some comments

* fix tests

* fix tests

* fixes from review

Closes #3180

* base verifier: bc->bv and check chainid

* improve some comments

* comments in dynamic verifier

* fix comment in doc about BaseVerifier

It requires the validator set to perfectly match.

* failing test for #2862

* move errTooMuchChange to types. fixes #2862

* changelog, comments

* ic -> dv

* update comment, link to issue

* Begin simple merkle compatibility PR

* Fix query_test

* Use trillian test vectors

* Change the split point per RFC 6962

* update spec

* refactor innerhash to match spec

* Update changelog

* Address @liamsi's comments

* Write the comment requested by @liamsi

* set the accum of a new validator to (-total voting power):

- disincentivize validators to unbond, then rebon to reset their
negative Accum to zero

additional unrelated changes:
- do not capitalize error msgs
- fix typo

* review comments: (re)capitalize errors & delete obsolete comments

* More changes suggested by @melekes

* WIP: do not batch clip (#2809)

* substract avgAccum on each iteration

- temporarily skip test

* remove unused method safeMulClip / safeMul

* always substract the avg accum

 - temp. skip another test

* remove overflow / underflow tests & add tests for avgAccum:

- add test for computeAvgAccum
- as we substract the avgAccum now we will not trivially over/underflow

* address @cwgoes' comments

* shift by avg at the end of IncrementAccum

* Add comment to MaxTotalVotingPower

* Guard inputs to not exceed MaxTotalVotingPower

* Address review comments:

 - do not fetch current validator from set again
 - update error message

* Address a few review comments:

 - fix typo
 - extract variable

* address more review comments:

 - clarify 1.125*totalVotingPower == totalVotingPower + (totalVotingPower >> 3)

* review comments: panic instead of "clipping":

 - total voting power is guarded to not exceed MaxTotalVotingPower ->
 panic if this invariant is violated

* fix failing test

* Swap start/end in ReverseIterator

* update CHANGELOG_PENDING

* fixes from review

* 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

* catch up with amino changes in
https://github.com/tendermint/go-amino/pull/222

* WIP: update to amino v0.13.0

* update to fixed amino release

* WIP: switching to fixed offsets for SignBytes

* add version field to sign bytes and update order

* more comments on test-cases and add a tc with a chainID

* remove amino:"write_empty" tag

- it doesn't affect if default fixed size fields ((u)int64) are
written or not
- add comment about int->int64 casting

* update CHANGELOG_PENDING

* update documentation

* add back link to issue #1622 in documentation

* remove JSON tags and add (failing test-case)

* fix failing test

* update test-vectors due to added `Type` field

* change Type field from string to byte and add new type alias

- SignedMsgType replaces VoteTypePrevote, VoteTypePrecommit and adds new
ProposalType to separate votes from proposal when signed

- update test-vectors

* fix remains from rebasing

* use SignMessageType instead of byte everywhere

* fixes from review

* Disable transitioning to new round upon 2/3+ of Precommit nils

Pull in ensureVote test function from https://github.com/tendermint/tendermint/pull/2132

* Add several ensureX test methods to wrap channel read with timeout

* Revert panic in tests

* tmlibs -> libs

* update changelog

* address some comments from review of #2298

* first commit

finalize rebase

add protoc_merkle to Makefile

* in progress

* fix kvstore

* fix tests

* remove iavl dependency

* fix tx_test

* fix test_abci_cli

fix test_apps

* fix test_apps

* fix test_cover

* rm rebase residue

* address comment in progress

* finalize rebase

* Implement issues 2386: add synchronization in lite verify and change all Certify to Verify

* Replace make(chan struct{}, 0) with make(chan struct{})

* Parameterize memroy cache size and add concurrent test

* Refactor import order

* Implement BFT time

* set LastValidators when creating state in state helper

for heights >= 2

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

Closes #2193

* Fix bug that was masked by custom Fmt!

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

This commit switches all usage of math/rand to cmn's rand. The only
exceptions are within the random file itself, the tools package, and the
crypto package. In tools you don't want it to lock between the go-routines.
The crypto package doesn't use it so the crypto package have no other
dependencies within tendermint/tendermint for easier portability.

Crypto/rand usage is unadjusted.

Closes #1343

make BlockMeta Header a non-pointer

Refs #693

This reverts commit d02c5d1e30.

Also, fix consensus liveness issue.

Refs #1740

also, expose limit option for number concurrent streams for gRPC
(unlimited by default)

This reverts commit 96a3502

* Reformated the ResultStatus

* fix misuse of ResultStatus.

* updated changelog

* Fixed tests

* fixed rpc helper tests

* fixed rpc_tests

* fixed mock/status_test

* fixed typo

* fixed ommitempty on validatorstatus and the changelog

* fixed extra line in changelog

* Updated usage of the /status json response in tests after breaking changes

* Updated remaining tests with changes after searching the codebase for usage

* Reformated the ResultStatus

* fix misuse of ResultStatus.

* updated changelog

* Fixed tests

* fixed rpc helper tests

* fixed rpc_tests

* fixed mock/status_test

* fixed typo

* fixed ommitempty on validatorstatus and the changelog

* Updated usage of the /status json response in tests after breaking changes

* Updated remaining tests with changes after searching the codebase for usage

* rebased against develop