WIP: Implement writes series data on database

* Add setSeriesId to raft, metastore
* Add methods to get seriesIds

[ci skip]
Implement setting of new series id
Finish up creating new series.

* setSeriesId changed to createSeriesIfNotExists
* changed tagsToBytes implementation to be more compact and accunt for maps not having keys in sorted order
* remove maxFieldId from database and use a sequence on the bucket for the db in the series bucket instead
Make writeSeries create shards if necessary and write data through.
Update write series

* don't block for replication when writing
* update db.CreateShardIfNotExists to return the shard
Update CreateSeriesIfNotExist to check for existence
Update CreateShardIfNotExists to check for shard first
Change getSeriesId to seriesID to be idomatic
Make errors all lowercase to be idomatic
Make ShardBySeriesTimestamp not exported
Remove todo
Update tagsToBytes to fix possible collisions
gofmt
Refactor CreateShardIfNotExist

* make createShardIfNotExist non-exported function
* make CreateShardsIfNotExist to create shards for a given block of time. Makes it so we don't need to expose series ids on exported functions.
Refactor CreateShardsIfNotExist to take policy name
Merge pull request #1165 from influxdb/write_series

Implement writes series data on database