Added Controller and linked keyPressed and SideBar to Controller

Also made some minor changes to the names of the variables in
constants.pde
Fixed reset bug of GameEngine
Fixed settings page when game has already started

Values now are final when the game has started
Defined the animate() of PixelEngine and resultsString of GameEngine
Added toggle feature for Sidebar
Added features to Controller

-Text becomes darker when controller isn't editable
-Defined codeString()
New sounds installed for game