Magic Mania 1.8: Summon Spells Rework and The Challenge System

Summon Guns and Summon Magic are no longer traditional spells.

When cast by the wizard, he gains a charge for his spell book but no antagonists are created, essentially making his life harder for more power. Both spells can only be cast once like this for a maximum of 2 extra charges.

When cast by very rare chance in summon events, no charages are gained, and there's a 10% chance of someone becoming a survivor, down from 25%.

When cast by a badmin they will be given a choice of not creating antags, creating antags at the old chance, or just going in stupid and giving everyone antag.

Technically fixes #5396