* Switched over to using Path (from NIO.2) rather than File for most operations.
* During unit testing now using an in-memory home path using ShrinkWrap.
* Further work on the new StorageManager, player stores now correctly invalidates references to entities destroyed while unloaded.
* Disabled disposal of materials for the moment, due to it glDeleteShader failing for some reason.
Continuing on developing the new StorageManager, starting to add support for saving to disk and restoring.
Implemented storage and restoring of global entities and core entity management state.
Initial work on chunk storage
- Removed Advanced Config and menu (dangerous, users shouldn't be messing with this)
 - A little cleanup.
Implemented core entity storage in chunk stores.
Added setBlockRetainComponent functionality to force a block to be retained
Some refactoring around the Storage Manager.
Merge remote-tracking branch 'upstream/multiplayer' into multiplayer