Added UntitledScroller, a singleton class that handles the mode that the
program is in.
Added LoadingScreen, which is currently only implementing screen, with
nothing else.
Added MainMenuScreen, which is currently only implementing screen, with
nothing else.
Revert "Added UntitledScroller, a singleton class that handles the mode that the"

This reverts commit a3053b000e33975c2fdb26df318a2b1071e68a4f.
Added UntitledScroller, a singleton class which handles the current 
mode the program is in.
Created LoadingScreen and MenuScreen, both of which currently implement
LibGDX's Screen class, with no other code yet in