NPC Buy() changes from original repo. Bonk fixes.

Buy() in monster.kod now handles mobs that sell from inventory (Izzio,Pacal).

Also included Bonk fixes here - the spell can no longer be cast on blind or dazzled players to occasionally allow them to see. Removed the DM restriction from the spell for the rare case where a player or monster will be able to cast the spell. These changes are in preparation of the soon-to-return bonksticks.