[rpc] DumpConsensusState: output state as json rather than string

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
      }
    }
  }
}
```

rpc/core/consensus.go

@@ -1,10 +1,13 @@
 package core
 
 import (
-	wire "github.com/tendermint/go-wire"
+	"encoding/json"
+
 	cm "github.com/tendermint/tendermint/consensus"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	"github.com/tendermint/tendermint/types"
+
+	"github.com/pkg/errors"
 )
 
 // Get the validator set at the given block height.
@@ -82,14 +85,22 @@ func Validators(heightPtr *int) (*ctypes.ResultValidators, error) {
 // }
 // ```
 func DumpConsensusState() (*ctypes.ResultDumpConsensusState, error) {
-	roundState := consensusState.GetRoundState()
-	peerRoundStates := []string{}
-	for _, peer := range p2pSwitch.Peers().List() {
+	roundStateBytes, err := json.Marshal(consensusState.GetRoundState())
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to marshal round state")
+	}
+
+	peerRoundStates := make(map[string]json.RawMessage)
+	for i, peer := range p2pSwitch.Peers().List() {
 		// TODO: clean this up?
 		peerState := peer.Get(types.PeerStateKey).(*cm.PeerState)
 		peerRoundState := peerState.GetRoundState()
-		peerRoundStateStr := peer.Key() + ":" + string(wire.JSONBytes(peerRoundState))
-		peerRoundStates = append(peerRoundStates, peerRoundStateStr)
+		peerRoundStateBytes, err := json.Marshal(peerRoundState)
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to marshal peer#%d round state", i)
+		}
+		peerRoundStates[peer.Key()] = json.RawMessage(peerRoundStateBytes)
 	}
-	return &ctypes.ResultDumpConsensusState{roundState.String(), peerRoundStates}, nil
+
+	return &ctypes.ResultDumpConsensusState{json.RawMessage(roundStateBytes), peerRoundStates}, nil
 }

rpc/core/types/responses.go

@@ -1,10 +1,11 @@
 package core_types
 
 import (
+	"encoding/json"
 	"strings"
 
 	abci "github.com/tendermint/abci/types"
-	"github.com/tendermint/go-crypto"
+	crypto "github.com/tendermint/go-crypto"
 	"github.com/tendermint/go-wire/data"
 	"github.com/tendermint/tendermint/p2p"
 	"github.com/tendermint/tendermint/types"
@@ -75,8 +76,8 @@ type ResultValidators struct {
 }
 
 type ResultDumpConsensusState struct {
-	RoundState      string   `json:"round_state"`
-	PeerRoundStates []string `json:"peer_round_states"`
+	RoundState      json.RawMessage   `json:"round_state"`
+	PeerRoundStates map[string]json.RawMessage `json:"peer_round_states"`
 }
 
 type ResultBroadcastTx struct {