Added Stat_Tracker class.

-keeps track of number of each action, and how many actions in each mood and age state.
-Also brings up a window when the monster dies, displaying these stats.  Takes care of closing monster window.
Sorted out some bugs from the program flow.

-Monster was aging when happy, mood label wasn't updating properly, incorrectly getting total number of actions
-Also changed balance slightly, but this makes it possible to keep the monster alive
Tweaked a few balance issues.

-Priority for mood (sad>hungry>bored>sleepy>dirty>happy) now matches the aging process (3 for sad, 2 for hungry/bored, 1 for sleepy/dirty, 0 for happy)
-Can no longer be sad without another status being achieved (ie 4 "low" stats but still sad, 1 must have achieved "medium")