Reimburses reagents when casting on mobs.

If a player casts a spell on a monster, he will find that spell's reagents in the monster's loot. This will only refund one cast of each spell, but refund reagents for different spells. I.e, if you cast 1xhold, 1xblind and 5xsplash of acid on a mob, you will find reagents for 1xhold,1xblind and 1xsplash of acid. 

This is to encourage people to use their spells while building, and make use of their entire arsenal, while discouraging mindless spamming of the same spell over and over and only killing the mob after 100 casts.