Implemented multi level.Modified Gamescreen class extensively, player
class, mainMenuScreen, and SpaceCatGame. Also modified game map because
I was having problems with that 1st jump.. was driving me nuts, so i
made it shorter!

Currently levels set to end at 4000 which is bit short -done for
debugging will extend later, also the bug with going past the
mainMenuScreen is here too after all 3 levels are passed. No screen for
end of level (since didn't have one) -it just jumps to the next level.

Implemented multi level.Modified Gamescreen class extensively, player
class, mainMenuScreen, and SpaceCatGame. Also modified game map because
I was having problems with that 1st jump.. was driving me nuts, so i
made it shorter!

Levels end at 4000, then just skips to the next level automatically -
need a level complete screen graphic? will extend levels - 4000 was just
for debugging.