Allow monster attacks in Arena. Repair Goad's Grinder, fix the spells that were failing in both Arenas. Misc bug fixes.

This fixes the bug where monsters were unable to fight in Arena battles. Tried pretty much every combo I can think of to break it. Earthquake, Heat and any other spell that has complex target requirements can now be cast in Arenas. Goad's Arena now works correctly and can also handle monster combat.

Goad's Grinder now has a unique function where you can log off during a fight and as long as you return within 30 seconds, it'll place you back into the fight, otherwise the fight will end.

I didn't implement real deaths in Goad's Grinder.

Also, I've increased the default duration of battles: Tos Arena traditional is 8 minutes, last man standing 12 minutes; Goad's Arena traditional is 10 minutes, last man standing is 14 minutes (not implemented yet).

Enchantments are now cleared from Arena after a fight ends.