Some code clean up

took out all the variable definitions in favor of just using this...not
sure if that is really the best way to go, but I think it is fine for
such a small state like the loading state.

I also cleaned up the callback code for starting the next state and made
it possible for the player to also click the mouse button to start the
game.

This functionality may be taken out altogether though. It may be best to
just load everything, start up a "splash" state to show the logo, then
start the "menu" state. Still deciding what would be the best course of
action.