Update 2.15

I replayed the game recently and found a few sticking points in the balancing...

The first optional boss (Blue Maelstrom) is no longer unintentionally and obscenely hard compared to every other boss in the game.

Boss reinforcements that aren't tied to special gimmicks show up a little bit more often.

Gave the final dungeon's bosses a bit more survivability.

And I squashed some bugs while I was at it.