Refactor reading

Major effects: effects preventing you from reading scrolls now
appear in MSGCH_PROMPT instead of the default channel, and
silence, water elementals, and ru's no-scrolls effect no longer
prevent you from reading books with (r). This also means that
those effects are only warned about after you finish choosing a
scroll through (r), rather than when you hit (r). If that seems
annoying, please remove the "read books with (r)" functionality.
Make Blurry Vision cause reading to take longer

Try number two (ref 6df881ba), but this time implemented as a
delay, such that it actually takes longer for e.g. tele to kick
in after you start trying to read the scroll.

Currently takes one extra turn for each level of the mutation
(so 1+1 turns at level 1, 2+1 for level 2, 3+1 for level 3).
Possibly it would be better for the last level to give 4+1.

TODO: Would be good if there was a DELAY_ARMOUR_* style chance to
cancel out of the reading midway through, but I ran into
technical issues with the implementation - its messaging caused
the interrupt to fire immediately every time...?
Move (r)ead checks back again

To the keypress, before slot selection.

This is more convenient for the common case (trying to read a
scroll), and less convenient for the case of 'trying to read a
spellbook while silenced' (or similar); in those cases, you're
back to having to use (i) to examine your spellbooks.
Improve curse weapon UI

Don't let players waste it when wielding a weapon of holy wrath;
and simplify.
Update blurry vision description
Gell's Gravitas.

A level 6 Hex/Translocation that pulls creatures towards a targeted
creature, potentially causing lots of collision damage - it's basically
a one-turn Singularity effect centered around a creature and without the
direct gravitational damage.

Appears in the book of the Warp and the book of Hinderance.

"Gell" is intended to be pronounced with a hard G.
Fix death message for collisions caused by the player character.

Was "caused by ", now is "caused by you".
Buff Singularity pull damage further.

My old testing of this was based on buggy mechanics; with the mechanics
fixed the spell proved to be underpowered.

This puts the damage slightly higher than it was in the original
implementation (d12 instead of d10 - a doubling over trunk as of the
previous commit), which puts it back at the previously established point
where it should be roughly as lethal as other level 9 spells.
Refactor away the trits array.

Also make chapter and verse 0-indexed (adding one on output only).

Hopefully this version is a little clearer?  It should give exactly
the same results as before.
Minor iterations for kobold and greatsword tiles.
Adjust Ru Sacrifice Hand description to account for species (chequers)
Let Pandemonium Lords buzz & croak

It's fun!
Rewrite Gell's Gravitas's description

Per request, to give it a bit more of a tloc feel.

The last sentence could use some work - a bit run-on right now.
Fix an oversight in Trog gifting code (7913)

and may the god of your choice help us all.
Improve animate skeleton messenging (3835)

In cases where there's no space to raise a skeleton.

this code is kind of bad
Deduplicate (Grunt)
Tweak a cloud hint message (gammafunk)

Tell the player what to do in response to the next prompt they'll
get (5 and . will just make the game nag them to hit Y or N,
which seems annoying?), and don't tell them to try to wait out
clouds unconditionally, since a lot of them (including those from
the first tutorial!) come from cloud generators. (So waiting isn't
a great solution...)

Still probably useful to suggest waiting, since some clouds *do*
vanish over time... idk.
Don't warn when glaciating IOODs

Or battlespheres.
Consolidate (reaverb)
Remove an unused parameter.