This commit, however, adds:
* Better support for background saves and loads.
* Periodical writes of region changes rather than explicit save() calls.
* Rewrite of the MySQL region code.
* Support for partial saves when using MySQL.
* Decoupling of region index implementations and RegionManager.
What still needs to be done includes:
* Background region modification operations (addmember, etc.).
* Unit tests to verify correctness of the partial saving.
* Migration support (to be re-added).
* Better handling when regions are failing to save.
* Testing of the /rg load and /rg save commands.
* Verification of how server shutdown / world unload is handled.
* Verification that thread-unsafe concurrent saves of data is not happening.
