Add Xom mood meter to webtiles.

This was added a few weeks ago to console and local tiles.

This isn't exactly the same, on console and local tiles the meter
turns red if Xom is getting BORED and lightred when Xom is BORED.
Unfortunately without making either an ugly hack or exposing
gift_timeout in the json this behavior can't be replicated in
webtiles; though the old colouring behavior was also not present
in webtiles so I'm guessing this isn't too big of a loss.
Hand-pick hell effect spawns

Mainly in reaction to shard shrike unpleasantness, but also as
an attempt to get better control over what's going on in hell.

The current list is a placeholder, very roughly aligned with the
coc population list.
Allow variation of fiend types for hell effects

And add shard shrikes for Coc.
Add more dragons to Coc hell effects (tarot)

Trade some ice dragons for bone dragons.
fix monster selection in a couple vaults

you.branch() returns "D", not "Dungeon"

see !lg RBrandon place=d:11 killer=lich 1 -tv:<0.5
use you.in_branch(foo) instead of you.branch() == foo

this way, we can get reasonable error messages if an invalid branch is
used

also fix a bug in ice2_lemuel related to this
Small improvements to yaktaur and yaktaur captain.
Value/saturation adjustments for several monster tiles.

Serpents of hell and Vaults denizens are the main ones.
Improvements to hippogriff, Nellie, and a couple skeletons.

Clarified bottom edge of silhouettes, adjusted shadows.
Fix beam knockback (#9334).
Remove two unused arrays.
Show spell stats while memorizing (9333)

Also preparation for something else I want to do.
Pull mons_spell_range into a separate function
Pull range_string into a separate function
Display monster spell ranges
Fix tiles compilation

??oops
Make range strings a little sillier

E.g., orc wizards now show o----> for throw flame instead of
@---->.

Not actually sure this is an improvement.
Changelog through 0.16-a0-3177-ge5ac76f