Improved lobby visual

-Added transperency to game list
-Colors now fetches from renderer, making them the same as the rest of
the game
-Lobby buttons now properly centered
-Size of game list is now based on the size of the center line
	-Horizontal size is 0.6 of the grey area
	-Vertical size is 0.9 of the grey area

TODO:
-Add scroll button so that all games are visible