Move PlayerQuit logic to mcMMOPlayer.logout()
Allow synchronous save on logout

This is intended for plugins that have foreknowledge of a logout
happening (e.g. a BungeeCord server hop about to happen), so that they
can tell mcMMO to save the data, and the new server will be able to pull
the profile correctly from the database.
Downgrade Bukkit to 1.7.9 to compile
Remove dead logoutParty() method
Merge pull request #2356 from riking/logout-method

This will allow for BungeeCord compat when the sending server knows about the move. It will NOT work if the proxy processes the transfer.