Refs #1755

I started with writing a test for wsConnection (WebsocketManager) where
I:

- create a WS connection
- do a simple echo call
- close it

No leaking goroutines, nor any leaking memory were detected.

For useful shortcuts see my blog post
https://blog.cosmos.network/debugging-the-memory-leak-in-tendermint-210186711420

Then I went to the rpc tests to see if calling Subscribe results in
memory growth. It did.

I used a slightly modified version of TestHeaderEvents function:

```
func TestHeaderEvents(t *testing.T) {
	// memory heap before
	f, err := os.Create("/tmp/mem1.mprof")
	if err != nil {
		t.Fatal(err)
	}
	pprof.WriteHeapProfile(f)
	f.Close()

	for i := 0; i < 100; i++ {
		c := getHTTPClient()
		err = c.Start()
		require.Nil(t, err)

		evtTyp := types.EventNewBlockHeader
		evt, err := client.WaitForOneEvent(c, evtTyp, waitForEventTimeout)
		require.Nil(t, err)
		_, ok := evt.(types.EventDataNewBlockHeader)
		require.True(t, ok)

		c.Stop()
		c = nil
	}

	runtime.GC()

	// memory heap before
	f, err = os.Create("/tmp/mem2.mprof")
	if err != nil {
		t.Fatal(err)
	}
	pprof.WriteHeapProfile(f)
	f.Close()

	// dump all running goroutines
	time.Sleep(10 * time.Second)
	pprof.Lookup("goroutine").WriteTo(os.Stdout, 1)
}
```

```
Showing nodes accounting for 35159.16kB, 100% of 35159.16kB total
Showing top 10 nodes out of 48
      flat  flat%   sum%        cum   cum%
32022.23kB 91.08% 91.08% 32022.23kB 91.08%  github.com/tendermint/tendermint/libs/pubsub/query.(*QueryParser).Init
 1056.33kB  3.00% 94.08%  1056.33kB  3.00%  bufio.NewReaderSize
  528.17kB  1.50% 95.58%   528.17kB  1.50%  bufio.NewWriterSize
  528.17kB  1.50% 97.09%   528.17kB  1.50%  github.com/tendermint/tendermint/consensus.NewConsensusState
  512.19kB  1.46% 98.54%   512.19kB  1.46%  runtime.malg
  512.08kB  1.46%   100%   512.08kB  1.46%  syscall.ByteSliceFromString
         0     0%   100%   512.08kB  1.46%  github.com/tendermint/tendermint/consensus.(*ConsensusState).(github.com/tendermint/tendermint/consensus.defaultDecideProposal)-fm
         0     0%   100%   512.08kB  1.46%  github.com/tendermint/tendermint/consensus.(*ConsensusState).addVote
         0     0%   100%   512.08kB  1.46%  github.com/tendermint/tendermint/consensus.(*ConsensusState).defaultDecideProposal
         0     0%   100%   512.08kB  1.46%  github.com/tendermint/tendermint/consensus.(*ConsensusState).enterNewRound
```

100 subscriptions produce 32MB.

Again, no additional goroutines are running after the end of the test
(wsConnection readRoutine and writeRoutine both finishes). **It means
that some exiting goroutine or object is holding a reference to the
*Query objects, which are leaking.**

One of them is pubsub#loop. It's using state.queries to map queries to
clients and state.clients to map clients to queries.

Before this commit, we're not thoroughly cleaning state.queries, which
was the reason for memory leakage.

Refs #951

Jae: I don't know a good way to catch these errors in general, but
forcing pubsub's internal channel to have a capacity of 0 will reveal
bugs sooner, if the subscriber also has a 0 or small capacity ch to pull
from.

to better handle zero cache size

* updateToState exits early if the state isn't new, which happens after
* fast syncing. This results in not sending a NewRoundStep message. The mempool
* reactor depends on PeerState, which is updated by NewRoundStep
* messages. If the peer never sends a NewRoundStep, the mempool reactor
* will think they're behind, and never forward transactions. Note this
* only happens when `create_empty_blocks = false`, because otherwise
* peers will move through the consensus state and send a NewRoundStep
* for a new step soon anyways. Simple fix is just to send the
* NewRoundStep message during updateToState even if exit early

update README

docs/spec: some organizational cleanup

add xla as codeowner

* all: gofmt

Run 'gofmt -w .' from project root.

* Update changelog to say that I ran gofmt

* Revert "Update changelog to say that I ran gofmt"

This reverts commit 956f133ff0.

Add algorithm for Blockchain Reactor

* circleci 2.0

typo fix

Refs #1736

Bump abci version

Xla/update develop v0120

Release/v0.12.0

* Remove error from priv.PubKey()

* Update changelog

* Switch ports 466xx to be 266xx
This is done so the default ports aren't in the linux kernel's default ephemeral port range.

* Update ABCI import

* Bump cache on circleci

* Get more verbose output for debugging

* Bump abci dependency

* Fix accidental change of a block header's hash

* pin abci release

* `unsafe_reset_all` also resets addrbook.json

When executing `unsafe_reset_all` it also clear all IP addresses from
addrbook.json. This is the expected behaviour of `unsafe_reset_all`.

* Fix tests

* improve logging statements

* use correct file

Resolve divergence

version bump

SignatureKey -> Signature

# Conflicts:
#	Gopkg.lock
#	keys/keybase_test.go
#	signature_test.go

include an example, do not err check on info ... bur for empty info
instead

return an error if we fail to parse external IP

Escape paths in config template

make PubKeyEd25519.Address() returns the first 20 bytes of the hash of the raw 32-byte pubkey, no amino required

Bech32: Wrap error messages