Translated Level class from c# (mostly)

Translated Level class from c# (mostly)

changed textrue from unsigned int to GLuint
added << for Point2D
World object implements ZOrder
got rid of SDL_Surface* screen from most items
moved text to class Text
Moved mName from Sprite to WorldObject
Added update behavior to sprites
Changed Loading to access loadinglevel instead of currentlevel (allowing loading of other levels)
Added framework for pausing and menu screens
changed currentlevel to int from uint so we can determine if the first level was loaded
Reworked background to use textures (draws again but doesn't wrap yet)

Implemented a lot of shit.