Remove an unneeded member from struct bolt.

Minor bug fix: fire crabs now get the whole path of fire clouds,
not just a cloud around the target.
Move ghost crabs from Crypt to Swamp.

Part of the original idea was to provide some sort of introduction to
the ghostly flame mechanic before the relatively rare revenants started
appearing. However, as part of Crypt's shortening, it became necessarily
more reliant on the end vault -- where revenants aren't quite as rare.
In general, the shortening meant that the place was too packed for there
to be any meaningful transition.

The other problem was the one that has plagued Crypt for a long time:
that there is no specific point in the game when it's played, leaving
the monsters to have poorly-defined strengths. The other monsters in
Crypt are very well-designed, so they manage to fit there better than
these new crabs.

Swamp is a good thematic fit, if you look at biology very vaguely. It also
already has minor undead and cloud themes that crabs can draw on. The
terrain should make dodging around the clouds interesting, I hope. They'll
be slightly less common than shambling mangrove, another nontraditional
summoner, and I think around the same danger level (they've probably
been too weak for Crypt).

The alternative here, of course, is removal. While I'd like to think that
I'm unbiased, the fact is that I'd like to see ghost crabs survive somewhere;
not as much, necessarily, because of being a good joke monster or my own
creation, but rather because of how much I liked the mechanic on revenants.
Simplify.
Change two of Kiku's titles to work better as player titles.

"Playername the X of Y" sounds better than "Playername the Y's X".
Remove an unncessary field of Branch.

We don't place uniques by absdepth anymore, so there's no need to
exclude these branches in code.
Deduplicate code slightly.