Remove a comment
Remove some Vehumet altars with books

Since Vehumet is no longer a book-gifting god, and will gift early
spells soon after being worshipped anyway.
Tweak punctuation.
Simplify some Ilsuiw speech.
Add Ilsuiw speech line.
Remove an old chaos spawn tile
Monster edits (roctavian, 6577)
Spiked and dire flails (roctavian, 6577)
Fix digging wands only digging a single space at a time
Improve monsters' use of Dig, and allow their use of wands of digging.

This sets up monsters to use Dig in scenarios where burrowing monsters
would burrow through walls, thus casting it instead of moving under the
right conditions. Given a charged wand of digging, they will use it
under the same circumstances.

This also adjusts the messaging when digging is observed in use to not
display even when the player doesn't see a target tile.
Adjust a couple of monster spell sets.

Jorgrun loses Leda's and Stoneskin and instead gets Dig (so he can
pursue the player relentlessly!).

Cacodemons get Dig back, by popular demand and due to the recent
improvements to dig behaviour.
Simplify.
Give arcane familiars M_SEE_INVIS.
Use stone glass for makhleb_altar_promises_db.

This prevents cacodemons, etc. from wandering about the level.
Make the "plain armour" acquirement code more internally consistent.
Don't always try to replace non-artefact body armour with slot-filling armour.
Make wands of invisibility more common.

They aren't very exciting even for most stabbers.

Compensate for this rarity change by making wands of enslavement less common.

Acquirement weights were adjusted in the opposite direction.
Don't try to place Rogue's Gallery on Crypt:$.

Since most of the layouts there involve encompass vaults, it's not a
good idea.
Fix some issues involving familiars and dead targets

Among other things, firing orders might not get purged correctly if a
target died from the player's spell before the familiar could fire. These
invalid firing orders could then stick around for a little while and possibly
cause a crash if the familiar's mindex because equal to its stored foe (for
example, following a level change)

This fixes #6584
Be even more careful about bad Familiar targetting.

Check for any invalid mindex, not just MHITYOU.

Also, print an error message if we do end up bailing because of AF
self-targetting.