types/heartbeat: test all Heartbeat functions

support historical abci queries

Release/0.11.1

[docs: typo fix] add missing "have"

[docs:typo fix] remove misplaced "the"

Leaving out params crashes tm rpc

https://github.com/tendermint/tendermint/pull/724#issuecomment-335362927

https://github.com/tendermint/tendermint/pull/724#issuecomment-335316484

so they can be used in rpc/core/types/responses.go.

```
So, it seems like we could use the actual structs here, but we don't want to have to import consensus to get them, as then clients are importing too much crap. So probably we should move some types from consensus into consensus/types so we can import.

Will these raw messages be identical to:

type ResultDumpConsensusState struct {
  RoundState cstypes.RoundState
  PeerRoundStates map[string]cstypes.PeerRoundState
}
```
https://github.com/tendermint/tendermint/pull/724#discussion_r143598193

Before:

```
{
  "jsonrpc": "2.0",
  "id": "",
  "result": {
    "round_state": "RoundState{\n  H:10 R:0 S:RoundStepNewHeight\n  StartTime:     2017-10-09 13:07:24.841134374 +0400 +04\n  CommitTime:    2017-10-09 13:07:23.841134374 +0400 +04\n  Validators:    ValidatorSet{\n      Proposer: Validator{EF243CC0E9B88D0161D24D733BDE9003518CEA27 {PubKeyEd25519{2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202}} VP:10 A:0}\n      Validators:\n        Validator{EF243CC0E9B88D0161D24D733BDE9003518CEA27 {PubKeyEd25519{2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202}} VP:10 A:0}\n    }\n  Proposal:      \u003cnil\u003e\n  ProposalBlock: nil-PartSet nil-Block\n  LockedRound:   0\n  LockedBlock:   nil-PartSet nil-Block\n  Votes:         HeightVoteSet{H:10 R:0~0\n      VoteSet{H:10 R:0 T:1 +2/3:\u003cnil\u003e BA{1:_} map[]}\n      VoteSet{H:10 R:0 T:2 +2/3:\u003cnil\u003e BA{1:_} map[]}\n    }\n  LastCommit: VoteSet{H:9 R:0 T:2 +2/3:947F67A7B85439AF2CD5DFED376C51AC7BD67AEE:1:365E9983E466 BA{1:X} map[]}\n  LastValidators:    ValidatorSet{\n      Proposer: Validator{EF243CC0E9B88D0161D24D733BDE9003518CEA27 {PubKeyEd25519{2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202}} VP:10 A:0}\n      Validators:\n        Validator{EF243CC0E9B88D0161D24D733BDE9003518CEA27 {PubKeyEd25519{2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202}} VP:10 A:0}\n    }\n}",
    "peer_round_states": []
  }
}
```

After:

```
{
  "jsonrpc": "2.0",
  "id": "",
  "result": {
    "round_state": {
      "Height": 1691,
      "Round": 0,
      "Step": 1,
      "StartTime": "2017-10-09T14:08:09.129491764+04:00",
      "CommitTime": "2017-10-09T14:08:08.129491764+04:00",
      "Validators": {
        "validators": [
          {
            "address": "EF243CC0E9B88D0161D24D733BDE9003518CEA27",
            "pub_key": {
              "type": "ed25519",
              "data": "2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202"
            },
            "voting_power": 10,
            "accum": 0
          }
        ],
        "proposer": {
          "address": "EF243CC0E9B88D0161D24D733BDE9003518CEA27",
          "pub_key": {
            "type": "ed25519",
            "data": "2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202"
          },
          "voting_power": 10,
          "accum": 0
        }
      },
      "Proposal": null,
      "ProposalBlock": null,
      "ProposalBlockParts": null,
      "LockedRound": 0,
      "LockedBlock": null,
      "LockedBlockParts": null,
      "Votes": {},
      "CommitRound": -1,
      "LastCommit": {},
      "LastValidators": {
        "validators": [
          {
            "address": "EF243CC0E9B88D0161D24D733BDE9003518CEA27",
            "pub_key": {
              "type": "ed25519",
              "data": "2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202"
            },
            "voting_power": 10,
            "accum": 0
          }
        ],
        "proposer": {
          "address": "EF243CC0E9B88D0161D24D733BDE9003518CEA27",
          "pub_key": {
            "type": "ed25519",
            "data": "2E0B9301334FCDAB193D514022F81BA09BBEC028685C96602BE9DD0BD4F9E202"
          },
          "voting_power": 10,
          "accum": 0
        }
      }
    },
    "peer_round_states": {
      "75EC8F15D244A421202F9725CD4DE509EE50303670310CF7530EF25E2B7C524B": {
        "Height": 1691,
        "Round": 0,
        "Step": 1,
        "StartTime": "2017-10-09T14:08:08.563251997+04:00",
        "Proposal": false,
        "ProposalBlockPartsHeader": {
          "total": 0,
          "hash": ""
        },
        "ProposalBlockParts": null,
        "ProposalPOLRound": -1,
        "ProposalPOL": null,
        "Prevotes": null,
        "Precommits": null,
        "LastCommitRound": 0,
        "LastCommit": null,
        "CatchupCommitRound": -1,
        "CatchupCommit": null
      }
    }
  }
}
```

Updates https://github.com/tendermint/tendermint/issues/693

* Adjusted Heartbeat.Copy to return nil on
trying to copy a nil value instead of panicking.
* Also documented that WriteSignBytes panics
if the Heartbeat is nil.

restore rpc/lib readme as doc.go (Refs #710) [ci skip]

I don't want to lose any documentation. Correct me if I am wrong, but we
don't have this docs anywhere else.

Unstable

Feature/no block response

get rid of anonymous imports

Fixes #514
Replaces #540

If a peer requests a block with a height that we don't have
respond with a bcNoBlockResponseMessage.
However, according to the Tendermint spec, if all nodes are honest
this condition shouldn't occur, so this is a possible hint of an
dishonest node.

How To Read Logs guide

document no empty blocks

Improve app dev docs