HordeTweaks

A few tweaks to hopefully make hordes of many a little more interesting. All changes are configurable.

• Hordes have a 10% chance to drop legendary items. This works the same way as boss item drops so mountain shrines and multiplayer give you more chances. The main reason hordes feel bad in vanilla in my opinion is they take away the chance of getting a cool boss item, hopefully this change makes that less of a problem.
• Max enemies increased (6 -> 36). This also makes hordes more varied since weaker enemies won't be considered too cheap as quickly.
• Hordes have a 5% chance to be deliberately chosen instead of a teleporter boss (in vanilla they can only be picked if a normal boss fails to spawn).