Vary layout_gridlike room shapes and add some per-branch variations

Also enabled it in Crypt and made it substantially more likely in Elf
Add a config option to allow undoing item glyph recolouring.

It's misnamed "0.12_monster_glyphs" for consistency with other such files,
even if it has not a single monster inside.

Having to list every fixed artefact is not nice, so some suggestion would
be good: it's not as straightforward as adding a "non-artefact" tag as no
one uses anchors so it'd match "artefact", and other tags wouldn't be
obvious enough.
Restore goddamned_bats.

Not because it's the best vault, but because it's a prominent reference
to a part of Crawl's history.  It has none of stated problems: corpses
work well, there are no "comes into view" problems (because of the genus
being correct).

This vault's removal has attracted a surprising amount of criticism, mostly
for emotional reasons, and not a single voice of approval.

I do agree some parts are silly, though: fruity bats and dwarf mountain bats
are ones I personally wouldn't shed a tear after.
Restore kb_skeletal_archery.

I think it's a good example of well designed one-off monsters:
* players intuitively know what the monster is, what to expect from it,
  and what it looks like, without having to read the description, or
  worse, spoilers.
* if they remained as plain "skeleton warriors", folks who play fast
  would be penalized for not reading that "comes into view, wielding
  a longbow" or being spoiled
* the vault actually provides some challenge: meeting a firing line
  can be deadly if you act stupidly

The vault could be made more aesthethic, though.
Remove an unused macro.
Fix spell-related commands being incredibly spammy if you know IMB.
Use 30 for sanity caps of all item enchantment types.

It was 30 for weapons, 25 for armour, which caused spam with Lear's.
Don't test missile enchantment values.
Reduce staff of energy hunger to zero once again.
Merge staves of energy and channeling.
Don't let mutations and vigour affect staff/rings of power.
Make staff of power's effect increase with your maxmp.

It gives 5 + 0.4 * maxmp, with anything above 50 being halved.
Formatting fixes.
Only generate goddamned_bats where it might possibly be dangerous.

Seriously, bats in Lair or Orc aren't interesting (and they are still free
piety for some gods).
Remove unnecessary absdepth check (tenofswords).
Make "You're too confused!" a canned message.
Say "You're too confused!" when interlevel travel is attempted while confused.
Restore an incorrectly removed desc.
Remove an incorrectly not removed desc.
Repair the desc for trog_wizard.