* types: change `Commit` to consist of just signatures

These are final changes towards removing votes from commit and leaving
only signatures (see ADR-25)

Fixes #1648

* bring back TestCommitToVoteSetWithVotesForAnotherBlockOrNilBlock

+ add absent flag to Vote to indicate that it's for another block

* encode nil votes as CommitSig with BlockIDFlagAbsent

+ make Commit#Precommits array of non-pointers
because precommit will never be nil

* add NewCommitSigAbsent and Absent() funcs

* uncomment validation in CommitSig#ValidateBasic

* add comments to ValidatorSet funcs

* add a changelog entry

* break instead of continue

continue does not make sense in these cases

* types: rename Commit#Precommits to Signatures

* swagger: fix /commit response

* swagger: change block_id_flag type

* fix merge conflicts

Refs #3262

* Removal of TotalTx & NumTx

- Removed totalTx and numTx

closes #2521

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* abci proto changes

* proto number fix

* txfilter_test fix

* comments on PR

* further changes

* bring back metrics

* fix indexer

* fix TestBlockMaxDataBytes and TestBlockMaxDataBytesUnknownEvidence

* indexer service back to header

* statistics.go fix

* fix ci

* listen for blocks, not headers

to be able to record txs throughput

* fix TestNetworkNewBlock

* fix tests

* fix tests in types package

* fixes after Anton's review

* fix tests

* bring back `consensus_total_txs` metric

I mistakenly thought it was removed.

* improve changelog

* remove LastBlockTotalTx from state

* docs: remove getNumTxs from BeginBlock Java example

- rename fields, methods, comments, tests

* types: test tm2pm on fully populated header

* upgrade for amino v0.13.0-rc0

* fix lint

* comment out final test

* use types.NewValidator

* node: set p2p.ProtocolVersion from state, not globals

* abci: update RequestInfo for versions

* abci: update ResponseInfo for versions

* compile fix

* fix test

* software_version -> version

* comment fix

* update spec

* add test

* comments and fix test

* types: add Version to Header

* abci: add Version to Header

* state: add Version to State

* node: check software and state protocol versions match

* update changelog

* docs/spec: update for versions

* state: more tests

* remove TODOs

* remove empty test

* require block.Time of the fist block to be genesis time

Refs #2587:

```
We only start validating block.Time when Height > 1, because there is no
commit to compute the median timestamp from for the first block. This
means a faulty proposer could make the first block with whatever time
they want.

Instead, we should require the timestamp of block 1 to match the genesis
time.

I discovered this while refactoring the ValidateBlock tests to be
table-driven while working on tests for #2560.
```

* do not accept blocks with negative height

* update changelog and spec

* nanos precision for test genesis time

* Fix failing test (#2607)

* Pass nil to NewValidatorSet() when genesis file's Validators field is nil

Closes: #2616

* Update CHANGELOG_PENDING.md

* remove ConsensusParams.TxSize and ConsensusParams.BlockGossip

Refs #2347

* block part size is now fixed

Refs #2347

* use max data size, not max bytes for tx limit

Refs #2347

* Implement BFT time

* set LastValidators when creating state in state helper

for heights >= 2

- state.MakeBlock takes a proposerAddr
- validateBlock only checks that the ProposerAddress is in the validator
  set
- fix raceyness from bad proposer test:
  - use privValidator to get the proposer address (instead of racy
    state)
  - note we had to remove the test that checked the correct proposer was
    included for higher rounds because we don't have a good way to test
    this with multiple consensus states and not using the
    privValidator.Address while calling createProposalBlock was a hack!

Refs #1134

Validation:

- ignored in block.ValidateBasic since it's stateful information
- checked in blockExec.ValidateBlock

This reverts commit d02c5d1e30.

This reverts commit 96a3502

Expose it in rpc client
Move ABCIResults into tendermint/types from tendermint/state

Add some tests.
Behaves like saving validator set, except it always saves at each height
instead of a reference to last changed.

State maintains LastResultsHash
Verify that we can produce unique hashes for each result,
and provide valid proofs from the root hash.

Update all BlockValidation that it matches the last state