Clean up some code duplication.

This also meant that shapeshifters wouldn't cast even natural spells
if they were in a spellcasting form, though right now there don't seem
to be any polymorph targets with both real and natural spells.
Clean up some dead code.

Monsters only casted if you weren't around in very specific circumstances,
so all the special-casing didn't do very much (it slightly affected
The Unspeakable's casting sometimes, I guess).

Also, ball lightnings don't have spells anymore.
AT_KITE and AT_SWOOP to replace devil mon-abils.

AT_KITE should work in any slot; AT_SWOOP only functions in the first
attack slot.

Now to make the hypothetical beast that has both.
Vault Wardens must hate you to seal doors (9196)

A warden must be nearby and have you as a foe to seal doors.
Otherwise, it's possible for a wandering summon or undead pal to
aggrevate the warden and then whack you from across the map. The
door-sealing mechanics are tied to you being the target, so it
doesn't make that much sense to allow wardens to target your summons
without rewriting that code.
Don't dereference a potentially null foe.
Tweak miscast summon numbers a bit more (theTower, #9197)

Some of these numbers were unintentionally high because of off-by-one
errors in counting loop iterations. Fix those and tweak a few others,
and change all the loops to use > 0 so confusion is less likely.

<theTower> 1-3 for spatials, 2-3 for aboms, 1-3 worldbinders, 1-2 common
           demons, 2 shadows, 2-4 giant mites, 1-2 fire vortices, 2-5
           random_mobile_monsters
Simplify?  Condense, anyway.
Monster Enslavement and Control Undead; give latter to anubis guards.

Monsters will only attempt to enslave your allies; Control Undead works
against anything undead in LOS (and breaks charms you've placed undead,
so they can re-Control your own controlled undead).

Yes, friendlies can use these spells; those doing so charm enemies (or
remove hexes).
A primitive implementation of monster Inner Flame.

Leverages the new "hex an ally of the target" logic for enslavement;
also targets the ally immediately afterwards for maximum explosive
factor.
Don't unintentionally buff mass confusion (gammafunk).
Don't describe quivered items as 'worn'
Fix Ash warning formatting (_Jordan_)

It is, wielding a scimitar of fixed bugs.
De-nerf FeMo (9169)

Fighters get !might now, and felid fighters specifically get
an extra 2 weapon skill. I strongly doubt that FeMo will be
'too strong'.

This partially reverts commit f05240ed176f5420229e56e39752b6794.
Reduce caustic shrike spawn frequency and band size.

Shrikes were responsible for a larger proportion of Depths kills than
seems desireable, so I've cut their spawn rate by 50% and afjusted band
size, usually downwards.
green rat -> river rat
make river rats amphibious
Nerf caustic shrikes, readjust spawn and pack size

After discussing in -dev, decreasing HD by 2, decreasing damage by 10%,
and slightly raising pack size and spawn rates. Spawn rate is still lower
than yesterday.
Properly handle autopickup for VS/Formicid under Sac Love. (HilariousDeathArtist)
Update changelog slightly.
Remove death knights

This zealot didn't add any particular novel experience, given that the
pre-temple gameplay is pretty similar to Necromancer, and starting w/
Yred means losing the interesting experience of picking a god in the
dungeon.