Don't crash when cleaving into a doomed SW.

Also pacified monsters on stairs, probably.  This is kind of a hack;
see the comment for suggestions for a better fix.
Allow abandoning religion while silenced

There's not balance issue here, and it simplifies a bad function.
Unify short & long contam descriptions

By making the former a bit closer to the latter.

Also hopefully silence some sign comparison warnings.
GDA EVP 25 -> 23

Doesn't need to have higher EVP than crystal plate; the resists
are nice but not *that* amazing.
Mostly de-randomize evp UC delay

It was difficult for players to tell what was going on (since it
was so very random), and unpredictable high-aut attacks could be
very unpleasant. There's a valid discussion about whether UC
needs to have a special heavy armour penalty at all (though I
think it does), but it doesn't need to be this nasty.

The new delay is very close to the old average delay; very
slightly lower at very low AEVP (< 5) and very slightly higher
above that. Armour delay is now completely eliminated at 3 AEVP
instead of 0, which is perhaps not ideal, but livable.
Move cast_dispersal into spl-transloc.cc

And remove the declaration of a long-gone function.
Reword MR resist message for fewer message collisions
Don't let black mark affect firewood

The demonspawn-shaped block of ice begins absorbing vital
energies! x27
Fix more zin debug spamminess
Add Hydra Form to Metamorphosis (simmarine)

And refactor.
Remove jump-attack

The ability never worked particularly well in its original form. Its
original intent was to combine attacking and translocation, but
because it ended up being a low-level ability, the attack become only
a tool to ensure the repositioning wasn't brokenly powerful rather
than a meaningful thing by itself. This was particularly true for
stabbing, which had to be disabled in jump-attack so that it didn't
break stealth. Boots of jumping never saw much use, and while there
are a few fans of felid jumping, that species already has tremendously
good positioning ability.

The shadow-step ability with Dithmenos uses the core jump-attack
targeting code and is similar to jump-attack in many ways. So fans of
jump-attack can worship Dith to get an ability that works better in
general because of shadow-step's very specific (and non-annoying)
targeting restrictions, its better range, and its not having awkward
compromises from trying to combine attack with movement on a ability
requiring no investment.

Despite the shared code with shadow-step, a lot of the code most in
need of refactoring was simply removed, including the interactions
with melee-attack. I enjoyed coding jump-attack back when I was
learning the codebase, especially finally figuring out the difficult
direction UI code. But now that the feature has evolved into something
better, I'm happy to see all this code and bad gameplay go the way of
item destruction. rip in peace.