UI call refactoring.

As my target is to firewall what data passes between the Engine<->GUI, making explict calls to the GUI is probably not what should happen most of the time. I've refactored all of the userInterface.method() calls use throughout the engine to instead call shim methods stuck in the primary TiTs class. The idea is to use the shims to do whatever data collection, modification, formatting or whatever that REQUIRES access to game state data, and THEN pass calls on to the GUI code. All GUI ever gets from the engine is base types (string/int/number/etc) and functions/args to blindly stuff into buttons for later usage.
addItemButton() is the first example of the kind of operation shimming I'm talking about, but considering where things will probably be going in short order, I've move EVERYTHING to using these types of shims. It also means blindly prefixing all calls with userInterface. is no longer required, although I may slightly rename the methods in GUI to force inadvertently-called methods to error. ie if you want to call addItemButton and call userInterface.addItemButton etc. (I might call them (doAddItemButton etc in the GUI code).

Eventually, GUI will lose its titsClassPtr:* hack, and everything will be forced to be pushed into the GUI by the engine, rather than the GUI making calls out to the engine to find things, basically airgapping how data gets into a displayable state.