Fix #674: graceful exit when having config file issues
Fix a few typos
GetLeaderRaftConnectString returns consistent result
Update database configuration to validate shard spaces before creating anything.

Fixes #860. Update the validate method on shard spaces to optionally check if the database exists.
Add optional pausing to data migration.
Merge pull request #861 from influxdb/860-validte-shards

Update database configuration to validate shard spaces before making db
Merge pull request #863 from influxdb/862-slow-data-migrator

Add optional pausing to data migration.
Don't ever try to query or write against a shard that is closed or deleted.

Uses a RWlock so there's no global lock on writes or queries.
Update CHANGELOG.md
Merge pull request #866 from influxdb/779-threadsafe-shard-deletion

Don't ever try to query or write against a shard that is closed or delet...
validate that shard spaces have a non-empty regex
Fix the changelog
Format @pauldix code
Merge pull request #857 from oliveagle/more_informative_api_get_servers

GetLeaderRaftConnectString returns consistent result
Merge pull request #856 from rubenk/fix-typo

Fix a few typos
Merge pull request #795 from DavidBord/fix-674-graceful-exit

Fix #674: graceful exit when having config file issues
Don't accidentally trigger continuous query backfilling
Merge pull request #887 from influxdb/fix-887

If the first continuous query to ever run on InfluxDB had backfill(false) InfluxDB will still backfill the data
Add invalid config file that should have been in #861. Whoops, sorry @jvshaid.
Fixes #868, panic on upgrades.

This was a problem with 0.7.x upgrades to 0.8 where there was a raft snapshot. The recovery method assumed certain structures would be there and they weren't.