Gumm's Harvest Moon - fixed memory leak

Note: For judging please use the final uploaded to pyweek.org.

The zip at the following location contains a bug fix for a memory leak that begins to affect performance after many achievements. The leak results in accumulation of multiple achievement sprites in the same slot, eventually overwhelming the game loop. The bug should not be a problem for normal judging experience. But if you wish to play a marathon session, then get this fix...

Version 1.1

Cheers.