Added BaseClass.
Made Render2D a singleton. cleaned up init code in Render2D class.
Added purging to Render2D so that Render2D is purged whenever a screen
is closed by the ScreenManager. This removes and disposes any children
currently on Stage2D.
Changed gpu render canvas class to accept displayObject2D for blitting.
Improved process method in ResourceManager to check if a resource has
already been processed and a force param to enforce processing it again
in any case.
Compiled SWC.
Improved extractNumber() method in DataParser.
Added registration of systems to class registry.