bump alpine version to 3.8

This is intended for use in a future PR for #2414

Fixes #2577

Fixes #2573

Closes #2525

* [libs/events] add more godoc comments
* [libs/events] refactor code
- improve var naming
- improve code structure
- do not use defers for unlocking mutexes (defer takes time)

* fix event concurrency flaw
* modify changelog
* fix a mistake
* fix a lint issue
* modify changelog
* modify for review issue
* modify for review issue
* modify for review issue

* Switch nodeID to be tmhash.Size, add test names for net addr tests
Both of these came up when locally trying to change tmhash size.
* fix error introduced by merge

Ref #2099

* specify time unit for FlushThrottleTimeout in TestP2PConfig
Refs #2555
* [tm-bench] refactor code
https://github.com/tendermint/tendermint/pull/2405#pullrequestreview-157166387

fix #2071

Signed-off-by: phymbert <pierrick.hymbert@gmail.com>

* abci: codespace

* changelog

* types: Remove pubkey from validator hash

* undo lock file change

* Update Spec

* Fix random distribution in bitArray.PickRandom

Previously it was very biased. 63 "_" followed by a single "x" had
much greater odds of being chosen. Additionally, the last element was
skewed. This fixes that by first preproccessing the set of all true
indices, and then randomly selecting a single element from there.

This commit also makes the code here significantly simpler, and
improves test cases.

* unlock mtx right after we select true indices

* first draft for ADR summarizing discussion from:
https://github.com/tendermint/tendermint/issues/1622

* fix link and add comment about pub-key per message and fix link

* fix link and add comment about pub-key per message; also:
 - fix link
 - add little diagram
 - fix typo

* Add a slightly different approach

* typo and ADR number

Bucky/adr 029

There's a time window after we call RotateFile() where autofile#index+1
does not exist. It will be created during the next call to Write(). BUT
if somebody calls NewReader() before Write(), it will fail with "open
  /tmp/wal#index+1/wal: no such file or directory"

We must create file (either by calling gr.Head.openFile() or directly)
during NewReader() to ensure read calls succeed.

Closes #2538

* docs: fix links

* docs: add readme from each section to the sidebar

* Disable transitioning to new round upon 2/3+ of Precommit nils

Pull in ensureVote test function from https://github.com/tendermint/tendermint/pull/2132

* Add several ensureX test methods to wrap channel read with timeout

* Revert panic in tests

also, fix potential bug in Or function

Also make reversing a slice more efficient

* timeouts as time.Duration are also breaking for old configs
* split BaseConfig#ValidateBasic into smaller methods

* docs: links to dirs need a slash

* docs/spec/abci: consensus params and general merkle

* remove some XXX

* config: remove Mempool.RecheckEmpty

* docs: remove recheck_empty

This change doubles the speed of the mempool's reaping.
Before:

BenchmarkReap-8   	    5000	    365390 ns/op	  122887 B/op

After:

BenchmarkReap-8   	   10000	    158274 ns/op	  122882 B/op

* minor doc cleanup

* docs/tools: link fixes and readme

* docs/networks: networks/local/README.md

* docs: update vuepress config

* docs: fixes from review

* tmlibs -> libs

* update changelog

* address some comments from review of #2298

* first commit

finalize rebase

add protoc_merkle to Makefile

* in progress

* fix kvstore

* fix tests

* remove iavl dependency

* fix tx_test

* fix test_abci_cli

fix test_apps

* fix test_apps

* fix test_cover

* rm rebase residue

* address comment in progress

* finalize rebase

* switch to amino for SignBytes and add Reply with error message

- currently only Vote is done

* switch Reply type in socket for other messages

 - add error description on error

* add TODOs regarding error handling

* address comments from peer review session (thx @xla)

 - contains all changes besides the test-coverage / error'ing branches

* increase test coverage:

 - add tests for each newly introduced error'ing code path

* return error if received wrong response

* add test for wrong response branches (ErrUnexpectedResponse)

* update CHANGELOG_PENDING and related documentation (spec)

* fix typo: s/CanonicallockID/CanonicalBlockID

* fixes from review

* Implement issues 2386: add synchronization in lite verify and change all Certify to Verify

* Replace make(chan struct{}, 0) with make(chan struct{})

* Parameterize memroy cache size and add concurrent test

* Refactor import order

docs: Add version

* add missing options to config.toml template and docs
Refs #2232
* config#ValidateBasic
Refs #2232
* [config] timeouts as time.Duration, not ints
Why:
- native type provides better guarantees than ", in ms" comment (harder
to shoot yourself in the leg)
- flexibility: you can change units