Re-added an AccessTranformer. Work to make sure new Gui System is
'Universally compatible' with mods that do stuff like NEI or ContentTips;
not clean, but effective... Deprecated SlotManager (using native code; for
compatibility). Added a call to guiTick() in MLGuiHandler.
Deleted deprecated class SlotManager. Also removed traces thereof.
Wrote a script that *should* automatically generate access transformers.