Fixed randart generation to correctly include/exclude arcane and antimagic...

Fixed randart generation to correctly include/exclude arcane and antimagic powers.  This should prevent certain rare cases of the Merchant generating inappropriate randarts for the player.
Random egos and powers can now be added to fixed arts and other objects.
Random Bosses have more consistent classes.
NPCs should not be spawned with incompatible equipment.
Oozemancers are anti-magic powered, and some NPCs have updated power sources so that they get the right equipment and are eligible for the right classes.
Added support for a .finish function in entities that is applied after resolvers are applied.