* Remove deprecated PanicXXX functions from codebase

As per discussion over
[here](https://github.com/tendermint/tendermint/pull/3456#discussion_r278423492),
we need to remove these `PanicXXX` functions and eliminate our
dependence on them. In this PR, each and every `PanicXXX` function call
is replaced with a simple `panic` call.

* add a changelog entry

Refs #3419

* Make sure config.TimeoutBroadcastTxCommit < rpcserver.WriteTimeout()

* remove redundant comment

* libs/rpc/http_server: move Read/WriteTimeout into Config

* increase defaults for read/write timeouts

Based on this article
https://www.digitalocean.com/community/tutorials/how-to-optimize-nginx-configuration

* WriteTimeout should be larger than TimeoutBroadcastTxCommit

* set a deadline for subscribing to txs

* extract duration into const

* add two changelog entries

* Update CHANGELOG_PENDING.md

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

* Update CHANGELOG_PENDING.md

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

* 12 -> 10

* changelog

* changelog

* 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>

* make BlockTimeIota a consensus parameter, not a locally configurable option

Refs #2920

* make TimeIota int64 ms

Refs #2920

* update Gopkg.toml

* fixes after Ethan's review

* fix TestRemoteSignerProposalSigningFailed

* update changelog

* bound mempool memory usage

Closes #3079

* rename SizeBytes to TxsTotalBytes

and other small fixes after Zarko's review

* rename MaxBytes to MaxTxsTotalBytes

* make ErrMempoolIsFull more informative

* expose mempool's txs_total_bytes via RPC

* test full response

* fixes after Ethan's review

* config: rename mempool.size to mempool.max_txs

https://github.com/tendermint/tendermint/pull/3248#discussion_r254034004

* test more cases

https://github.com/tendermint/tendermint/pull/3248#discussion_r254036532

* simplify test

* Revert "config: rename mempool.size to mempool.max_txs"

This reverts commit 39bfa36961.

* rename count back to n_txs

to make a change non-breaking

* rename max_txs_total_bytes to max_txs_bytes

* format code

* fix TestWALPeriodicSync

The test was sometimes failing due to processFlushTicks being called too
early. The solution is to call wal#Start later in the test.

* Apply suggestions from code review

* 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>

* add ResetTestRootWithChainID

* modify chainid

* 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

* config: cors options are arrays of strings, not strings

Fixes #2980

* docs: update tendermint-core/configuration.html page

* set allow_duplicate_ip to false

* in `tendermint testnet`, set allow_duplicate_ip to true

Refs #2712

* fixes after Ismail's review

* Revert "set allow_duplicate_ip to false"

This reverts commit 24c1094ebc.

Refs #2877

* Introduce a structured logging option

* rename StructuredLog to LogFormat

* add changelog entry

* move log_format under log_level

* validate reactor messages

Refs #2683

* validate blockchain messages

Refs #2683

* validate evidence messages

Refs #2683

* todo

* check ProposalPOL and signature sizes

* add a changelog entry

* check addr is valid when we add it to the addrbook

* validate incoming netAddr (not just nil check!)

* fixes after Bucky's review

* check timestamps

* beef up block#ValidateBasic

* move some checks into bcBlockResponseMessage

* update Gopkg.lock

Fix

```
grouped write of manifest, lock and vendor: failed to export github.com/tendermint/go-amino: fatal: failed to unpack tree object 6dcc6ddc14
```

by running `dep ensure -update`

* bump year since now we check it

* generate test/p2p/data on the fly using tendermint testnet

* allow sync chains older than 1 year

* use full path when creating a testnet

* move testnet gen to test/docker/Dockerfile

* relax LastCommitRound check

Refs #2737

* fix conflicts after merge

* add small comment

* some ValidateBasic updates

* fixes

* AppHash length is not fixed

* require block.Time of the fist block to be genesis time

Refs #2587:

```
We only start validating block.Time when Height > 1, because there is no
commit to compute the median timestamp from for the first block. This
means a faulty proposer could make the first block with whatever time
they want.

Instead, we should require the timestamp of block 1 to match the genesis
time.

I discovered this while refactoring the ValidateBlock tests to be
table-driven while working on tests for #2560.
```

* do not accept blocks with negative height

* update changelog and spec

* nanos precision for test genesis time

* Fix failing test (#2607)

* remove some XXX

* config: remove Mempool.RecheckEmpty

* docs: remove recheck_empty

* add missing options to config.toml template and docs
Refs #2232
* config#ValidateBasic
Refs #2232
* [config] timeouts as time.Duration, not ints
Why:
- native type provides better guarantees than ", in ms" comment (harder
to shoot yourself in the leg)
- flexibility: you can change units

* 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

Why:
original fork is abandoned and not supported anymore.

Changes:
- LevelDB 1.19 (LevelDB and Snappy are both compiled and linked statically, so while you will not need them installed on your target machine, you should have a roughly compatible version of libstdc++.)
- snappy and lz4 libs included by default

* addr_book_strick=false on local nets

* link to spec

* spec: remove TODO, see #1749 instead

* spec: make issues from TODOs

* update docs on addr_book_strict option

* db_path is not being parsed

Fix default configuration, db_path is now db_dir.

Closes: cosmos/cosmos-sdk#1712

* Update CHANGELOG_PENDING.md

* [p2p/pex] connect to more than 10 peers

also, remove DefaultMinNumOutboundPeers because a) I am not sure it's
needed b) it's super confusing

look closely

```
maxPeers := sw.config.MaxNumPeers - DefaultMinNumOutboundPeers
if maxPeers <= sw.peers.Size() {
  sw.Logger.Info("Ignoring inbound connection: already have enough peers", "address", inConn.RemoteAddr().String(), "numPeers", sw.peers.Size(), "max", maxPeers)
```

we print maxPeers = config.MaxPeers - DefaultMinNumOutboundPeers. So we
may not have enough peers even though we say we have enough.

Refs #2130

* update spec

* replace MaxNumPeers with MaxNumInboundPeers/MaxNumOutboundPeers

Refs #2130

* update changelog

* make max rpc conns formula visible to users

* update spec

* docs: note max outbound peers excludes persistent

also, add `priv_validator_laddr` to the template

* 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 d02c5d1e30.

* limit the number of requests in flights for Prometheus server

Closes #1804

Default to 1 because usually there's just one collector.

* config: Up default for prom connections

* new config option for external address to advertise
* if blank, defaults to best guess from listener
* if laddr ip address is also blank, default to IPv4

except now we calculate the max size using the maxPacketMsgSize()
function, which frees developers from having to know amino encoding
details.

plus, 10 additional bytes are added to leave the room for amino upgrades
(both making it more efficient / less efficient)

* config: rename skip_upnp to upnp

Change default option to enable upnp.

Closes #1806

* doc updates

- fix comment and set UPNP to false in TestP2PConfig
- add UPNP to config template
- update changelog

Refs #1740

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

This reverts commit 96a3502

As we didn't hear any voices requesting this feature, we removed the
option to disable it and always have peer connection auth encrypted.

closes #1518
follow-up #1325

Refs #345

* improve testnet cmd

* allow non-validators
* configurable prefix
* populating of persistent peers

* relax permissions

* cleanup output dir every time

* do not remove dir

* remove panic comments

Closes #1428