Scene GameObject structure

Laying out structure for certain components, and a place to put global
scripts.
Creation of a MainMenuController script
Impl. of MainMenuController
Stub MainMenuSkin
Attached MainMenuScript to GUI GameObject

Because the Main Menu GUI belongs here
Stub of GlobalPauseController Script
Refactor pause controls into the pause controller
Refactor MainMenuController to MainMenuGUIController
GPLv3ed everything