Trimming and refactoring

-Cut down the Tracker type so it no longer collects data needed only by
the old fitness function
-Creating the fast sampling function for action and state matrices no
longer requires the use of the bulky Alias record; now uses a more
functional style
-Renamed some functions for clarity
-Improved information displayed by the console window; now the long-time
average of the best member of each generation is displayed. This also
gives a good idea of how long each generation takes.