Somehow my previous attempt to fix this test was somewhat
non-deterministic. I think I misjudged how the "median" would impact
the test.
I ran the test in question 10 times without seeing a failure (which
would show up 10-30% of the time previously,) so I'm pretty sure this
is fixed.
Fixes#828. Adds state sync, as outlined in [ADR-053](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-053-state-sync-prototype.md). See related PRs in Cosmos SDK (https://github.com/cosmos/cosmos-sdk/pull/5803) and Gaia (https://github.com/cosmos/gaia/pull/327).
This is split out of the previous PR #4645, and branched off of the ABCI interface in #4704.
* Adds a new P2P reactor which exchanges snapshots with peers, and bootstraps an empty local node from remote snapshots when requested.
* Adds a new configuration section `[statesync]` that enables state sync and configures the light client. Also enables `statesync:info` logging by default.
* Integrates state sync into node startup. Does not support the v2 blockchain reactor, since it needs some reorganization to defer startup.
Sam Kleinman
Erik Grinaker
Aleksandr Bezobchuk
Anton Kaliaev
Marko