Added levels and classes to character builder

Character builder can now incorporate character
level and class into its output. Players can
see what sort of stats result from picking a
class, level, and then allocating the player
points to desired attributes. Pretty cool.

This is a first pass. Code is shitty - almost
no comments or error-checking, bad variable names,
no tests, etc. etc. Still need to add the 'random
allocation' method too.