change the default corpse and skeleton item glyph
also differentiate staves and rods
the singular of "staves" is "staff"
Flatten & pull out some deck name code

name_aux is a small abomination.
Make some dbg-scan bad item checks arguably less bad
update options_guide.txt
remove dec, ibm, and old_unicode as csets

if you really want them, the display_char settings for them have been
moved to settings/dec_glyphs.txt, settings/ibm_glyphs.txt, and
settings/old_unicode_glyphs.txt.
apparently this is no longer dependent on char_set (wheals)
fix bad item crashes (PleasingFungus)
Restrict useless:darkgrey default to potions, scrolls, jewellery.

It was confusing on missiles (a javelin thrown at you should differ from a large
rock, even if you cannot use either) and misleading for armours when it comes to
mutations (e.g. claws 3 rendering gloves "useless", not not permanently so.)
Make Lajatang of Order read {silver, rMut} again (ChrisOelmueller).

The comma disappeared with 8677afe9, but it should still be there to
reflect the pseudobrand (cf. Hellfire).
Remove some Minor Healing

Norris's: he's a death cultist, not a healer!

Wizards': It fit their theme back when 'holy' was a spellschool,
but it ain't now, and it isn't particularly useful for them now.

Dowan's. 2d1.
Make Norris follow the one true god

GOD_NAMELESS.

Very silly for a 'death cultist' to be casting spells like a
wizard!
Unionize

Change a number of item fields to use unions, in the interests of
readability/sanity. All uses of plus2 are enumerated; plus and
special are only partially enumerated. Someone should probably
do a second pass, at some point.

Also removes a few archaic uses of plus2, e.g. its use in
randbook generation, which had been obsolete since 86acd0ce5263,
and adds a function for checking if a wand is known to be empty.
(Sorry, that one should be in a separate commit - too hard to
separate out now...)
A pile of vaults from various authors (#8862, #9036, #9101).

Changes:

cheibrodos_lair_reptile_den: move the black mambas to the 2 glyph.

cheibrodos_magma_flow: lava worms no longer exist; replaced with lava
snakes.

cheibrodos_lair_caveside_slide: nuked the SHUFFLE that broke
connectivity, adjusted the SUBST: to match, and removed the now-unused -
glyph.

cheibrodos_spurs: removed the extra 0 placement; having the enemies
place in bands probably makes this sufficiently threatening.

kennysheep_kobold_grotto: killed the neutral halflings (they're corpses
now).

kennysheep_(vaults_)gozag_temple: added a uniq_ tag so that only one
appears per game; halved the greed of the shops, but limit the number
of items in each shop to three; decoloured the glass; coloured the
statues; removed entry-by-stairs (it is a gimmick that has been overdone
and is aggravating).

nicolae_ru_great_annihilating_truth: remove the monster from the altar
and shuffle it into one of the four external monster slots instead.

nicolae_ru_awakened_eye: per author, change the iris to shallow water
to distinguish it from the outer eye.
Cleanup (Grunt, |amethyst)

Unused variable, variable with shadowed name, weird field sizes.
Further de-warning.

<PleasingFungus> Grunt: remove it yourself!!!
Add a spooky surprise!

Tile is credit (Bloax). Grunt & gammafunk also helped!
Fix another warning.
Unbrace.