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

And typo fix

* move from tmlibs 213
* expose KVPair, simpleproofsfrommap returns keys

* Return errors on priv.Sign(), priv.PubKey()

* Add CreateLedger, CreateOffline

* Add switch on .Sign() for Ledger wallets

* Add offline signing switch on .Sign()

* Use MustUnmarshalBinaryBare()

* Add confirmation to delete offline/Ledger keys

* Lowercase error message

* Add human-readable .GetType() function to Info interface

* Rename CryptoAlgo => SignAlgo

* assert.Nil(t, err) => assert.NoError(t, err)

```
I[06-08|11:51:57.234] Getting UPNP external address                module=p2p
I[06-08|11:51:58.867] Got UPNP external address                    module=p2p address=
```

Fixes #1717

```
I[06-08|11:51:56.952] Starting multiAppConn                        module=proxy impl=multiAppConn
I[06-08|11:51:56.952] Starting localClient                         module=abci-client connection=query impl=localClient
I[06-08|11:51:56.952] Starting localClient                         module=abci-client connection=mempool impl=localClient
I[06-08|11:51:56.952] Starting localClient                         module=abci-client connection=consensus impl=localClient
I[06-08|11:51:56.952] ABCI Handshake                               module=consensus appHeight=0 appHash=
I[06-08|11:51:56.952] ABCI Replay Blocks                           module=consensus appHeight=0 storeHeight=0 stateHeight=0
I[06-08|11:51:57.053] Completed ABCI Handshake - Tendermint and App are synced module=consensus appHeight=0 appHash=
I[06-08|11:51:57.053] This node is a validator                     module=consensus addr=6816B5D9BAC32A3CDF07884D9D3D2650694C371D pubKey=PubKeyEd25519{27A40CD032DD2467342D0CF27C5EC92052D966FEC714B6CF2F3BF3146AFD0D51}
I[06-08|11:51:57.234] Starting Node                                module=main impl=Node
I[06-08|11:51:57.234] Starting EventBus                            module=events impl=EventBus
I[06-08|11:51:57.234] Local listener                               module=p2p ip=:: port=46656
I[06-08|11:51:57.234] Getting UPNP external address                module=p2p
I[06-08|11:51:58.867] Got UPNP external address                    module=p2p address=
I[06-08|11:51:58.867] Starting DefaultListener                     module=p2p impl=Listener(@<nil>:46656)
I[06-08|11:51:58.867] P2P Node ID                                  module=main ID=3629b516392e494ae717ac4c6a1ea7eb0fe421c3 file=/home/tpb/.tendermint/config/node_key.json
I[06-08|11:51:58.868] Add our address to book                      module=p2p book=/home/tpb/.tendermint/config/addrbook.json addr=null
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x38 pc=0x89fb86]

goroutine 1 [running]:
github.com/tendermint/tendermint/p2p.(*NetAddress).String(0x0, 0xc96e24, 0x17)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/p2p/netaddress.go:171 +0x26
github.com/tendermint/tendermint/p2p/pex.(*addrBook).AddOurAddress(0xc420190620, 0x0)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/p2p/pex/addrbook.go:160 +0x116
github.com/tendermint/tendermint/node.(*Node).OnStart(0xc420286d00, 0xc4201b8010, 0xd)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/node/node.go:402 +0x547
github.com/tendermint/tendermint/vendor/github.com/tendermint/tmlibs/common.(*BaseService).Start(0xc420286d00, 0xe51c40, 0xc42000bd40)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/vendor/github.com/tendermint/tmlibs/common/service.go:130 +0x3bd
github.com/tendermint/tendermint/cmd/tendermint/commands.NewRunNodeCmd.func1(0xc42022e000, 0xc4200acdc0, 0x0, 0x1, 0x0, 0x0)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/cmd/tendermint/commands/run_node.go:58 +0xfe
github.com/tendermint/tendermint/vendor/github.com/spf13/cobra.(*Command).execute(0xc42022e000, 0xc4200acda0, 0x1, 0x1, 0xc42022e000, 0xc4200acda0)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/vendor/github.com/spf13/cobra/command.go:762 +0x468
github.com/tendermint/tendermint/vendor/github.com/spf13/cobra.(*Command).ExecuteC(0x1289280, 0xbbdda0, 0xc420015e01, 0xc4201bc640)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/vendor/github.com/spf13/cobra/command.go:852 +0x30a
github.com/tendermint/tendermint/vendor/github.com/spf13/cobra.(*Command).Execute(0x1289280, 0xc4201bc640, 0xc420015e98)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/vendor/github.com/spf13/cobra/command.go:800 +0x2b
github.com/tendermint/tendermint/vendor/github.com/tendermint/tmlibs/cli.Executor.Execute(0x1289280, 0xde5798, 0x2, 0xc4200332c0)
	/home/tpb/code/go/src/github.com/tendermint/tendermint/vendor/github.com/tendermint/tmlibs/cli/setup.go:89 +0x4e
main.main()
	/home/tpb/code/go/src/github.com/tendermint/tendermint/cmd/tendermint/main.go:45 +0x24d
```