* use READ lock/unlock in ConsensusState#GetLastHeight

Refs #2721

* do not use defers when there's no need

* fix peer formatting (output its address instead of the pointer)

```
[54310]: E[11-02|11:59:39.851] Connection failed @ sendRoutine              module=p2p peer=0xb78f00 conn=MConn{74.207.236.148:26656} err="pong timeout"
```

https://github.com/tendermint/tendermint/issues/2721#issuecomment-435326581

* panic if peer has no state

https://github.com/tendermint/tendermint/issues/2721#issuecomment-435347165

It's confusing that sometimes we check if peer has a state, but most of
the times we expect it to be there

1. add79700b5/mempool/reactor.go (L138)
2. add79700b5/rpc/core/consensus.go (L196) (edited)

I will change everything to always assume peer has a state and panic
otherwise

that should help identify issues earlier

* abci/localclient: extend lock on app callback

App callback should be protected by lock as well (note this was already
done for InitChainAsync, why not for others???). Otherwise, when we
execute the block, tx might come in and call the callback in the same
time we're updating it in execBlockOnProxyApp => DATA RACE

Fixes #2721

Consensus state is locked

```
goroutine 113333 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00180009c, 0xc0000c7e00)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*RWMutex).RLock(0xc001800090)
        /usr/local/go/src/sync/rwmutex.go:50 +0x4e
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).GetRoundState(0xc001800000, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:218 +0x46
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusReactor).queryMaj23Routine(0xc0017def80, 0x11104a0, 0xc0072488f0, 0xc007248
9c0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/reactor.go:735 +0x16d
created by github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusReactor).AddPeer
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/reactor.go:172 +0x236
```

because localClient is locked

```
goroutine 1899 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00003363c, 0xc0000cb500)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*Mutex).Lock(0xc000033638)
        /usr/local/go/src/sync/mutex.go:134 +0xff
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client.(*localClient).SetResponseCallback(0xc0001fb560, 0xc007868540)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client/local_client.go:32 +0x33
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy.(*appConnConsensus).SetResponseCallback(0xc00002f750, 0xc007868540)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy/app_conn.go:57 +0x40
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state.execBlockOnProxyApp(0x1104e20, 0xc002ca0ba0, 0x11092a0, 0xc00002f750, 0xc0001fe960, 0xc000bfc660, 0x110cfe0, 0xc000090330, 0xc9d12, 0xc000d9d5a0, ...)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state/execution.go:230 +0x1fd
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state.(*BlockExecutor).ApplyBlock(0xc002c2a230, 0x7, 0x0, 0xc000eae880, 0x6, 0xc002e52c60, 0x16, 0x1f927, 0xc9d12, 0xc000d9d5a0, ...)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state/execution.go:96 +0x142
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).finalizeCommit(0xc001800000, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1339 +0xa3e
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).tryFinalizeCommit(0xc001800000, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1270 +0x451
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).enterCommit.func1(0xc001800000, 0x0, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1218 +0x90
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).enterCommit(0xc001800000, 0x1f928, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1247 +0x6b8
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).addVote(0xc001800000, 0xc003d8dea0, 0xc000cf4cc0, 0x28, 0xf1, 0xc003bc7ad0, 0xc003bc7b10)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1659 +0xbad
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).tryAddVote(0xc001800000, 0xc003d8dea0, 0xc000cf4cc0, 0x28, 0xf1, 0xf1, 0xf1)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1517 +0x59
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).handleMsg(0xc001800000, 0xd98200, 0xc0070dbed0, 0xc000cf4cc0, 0x28)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:660 +0x64b
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).receiveRoutine(0xc001800000, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:617 +0x670
created by github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).OnStart
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:311 +0x132
```

tx comes in and CheckTx is executed right when we execute the block

```
goroutine 111044 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00003363c, 0x0)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*Mutex).Lock(0xc000033638)
        /usr/local/go/src/sync/mutex.go:134 +0xff
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client.(*localClient).CheckTxAsync(0xc0001fb0e0, 0xc002d94500, 0x13f, 0x280, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client/local_client.go:85 +0x47
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy.(*appConnMempool).CheckTxAsync(0xc00002f720, 0xc002d94500, 0x13f, 0x280, 0x1)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy/app_conn.go:114 +0x51
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/mempool.(*Mempool).CheckTx(0xc002d3a320, 0xc002d94500, 0x13f, 0x280, 0xc0072355f0, 0x0, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/mempool/mempool.go:316 +0x17b
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/core.BroadcastTxSync(0xc002d94500, 0x13f, 0x280, 0x0, 0x0, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/core/mempool.go:93 +0xb8
reflect.Value.call(0xd85560, 0x10326c0, 0x13, 0xec7b8b, 0x4, 0xc00663f180, 0x1, 0x1, 0xc00663f180, 0xc00663f188, ...)
        /usr/local/go/src/reflect/value.go:447 +0x449
reflect.Value.Call(0xd85560, 0x10326c0, 0x13, 0xc00663f180, 0x1, 0x1, 0x0, 0x0, 0xc005cc9344)
        /usr/local/go/src/reflect/value.go:308 +0xa4
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.makeHTTPHandler.func2(0x1102060, 0xc00663f100, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/handlers.go:269 +0x188
net/http.HandlerFunc.ServeHTTP(0xc002c81f20, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:1964 +0x44
net/http.(*ServeMux).ServeHTTP(0xc002c81b60, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:2361 +0x127
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.maxBytesHandler.ServeHTTP(0x10f8a40, 0xc002c81b60, 0xf4240, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/http_server.go:219 +0xcf
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.RecoverAndLogHandler.func1(0x1103220, 0xc00121e620, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/http_server.go:192 +0x394
net/http.HandlerFunc.ServeHTTP(0xc002c06ea0, 0x1103220, 0xc00121e620, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:1964 +0x44
net/http.serverHandler.ServeHTTP(0xc001a1aa90, 0x1103220, 0xc00121e620, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:2741 +0xab
net/http.(*conn).serve(0xc00785a3c0, 0x11041a0, 0xc000f844c0)
        /usr/local/go/src/net/http/server.go:1847 +0x646
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:2851 +0x2f5
```

* consensus: use read lock in Receive#VoteMessage

* use defer to unlock mutex because application might panic

* use defer in every method of the localClient

* add a changelog entry

* drain channels before Unsubscribe(All)

Read 55362ed766/libs/pubsub/pubsub.go (L13)
for the detailed explanation of the issue.

We'll need to fix it someday. Make sure to keep an eye on
https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-033-pubsub.md

* retry instead of panic when peer has no state in reactors other than consensus

in /dump_consensus_state RPC endpoint, skip a peer with no state

* rpc/core/mempool: simplify error messages

* rpc/core/mempool: use time.After instead of timer

also, do not log DeliverTx result (to be consistent with other memthods)

* unlock before calling the callback in reqRes#SetCallback

* Add test showing normal Sync call

* Show hanging response if server dies during BeginBlock

* Flush all in-flight requests on shutdown, not just pending requests

* Add bugfix to CHANGELOG

This reverts commit d02c5d1e30.