Adv color handling, IxSet implem, pretty printer

Cards/Common/Color.hs : Complicated color instances and definitions
Cards/Common/Invotomorph.hs : class for theseus-like automorphic
involutions (f(a) = b <==> f(b) = a, a and b of same type)
Cards/Pretty.hs : Experimental ASCII-art representation of cards
Database.hs now has working implementation of IxSet