Mysql: save master hostname with log position info

When restoring, it's really helpful to programmatically know the
hostname of the machine that the snapshot came from, otherwise you're
just hoping that the master you will connect to is the same master that
the snapshotted slave replicating from.
Merge save-hostname-of-master (#3) into ifixit-production

Mysql: save master hostname with log position info

When restoring, it's really helpful to programmatically know the
hostname of the machine that the snapshot came from, otherwise you're
just hoping that the master you will connect to is the same master that
the snapshotted slave replicating from.