MySQL DataStore Overhaul

These changes also allow for easy table splitting and connection pool changes for possible future enhancements.
It is possible, but generally all of the queries were broken into individual subject/attribute pairs so that I could build each query to make the best use of the indexes and potentially look at breaking up tables.  For example instead of engaging the regex engine and using aff4:/.* I split all those and use prefix=aff4 to take advantage of the index.  

Performance wise the bulk queries were showing up in slow queries log pretty consistently and now the only things showing up are stats_store and hunts queries.  Though that doesn't mean that the total time isn't longer.  It does seem to help in allowing multiple frontends/workers get stuff done without running into deadlocks or get stuck waiting for locks.  InnoDB and having the connection pool retry queries helps with that as well.