Remove Control Teleport from Books

Remove cTele from Fixed Books, which will remove it from rand books.
Restricting it to items will typically force the use of a ring slot.
Constify.
Add an %alpha directive for tile processors

Alpha is applied after all other recolour filters. It multiples the alpha
channel of the image by a given value in the range [1..255]. 0 is not
allowed as this would just make the image fully transparent. 127 is 50%
transparency, 255 is equivalent to no change.

The syntax is: %alpha [value]
Add TILE_FLAG_WEB to tile_flags and shuffle TILE_FLAG_ANIM_WEP to end

High-valued flags don't appear to apply correctly to the
player, although they apply fine to monsters.
Display a different overlay when player or monster held by a web

For now it's a semi-transparent version of a normal web. It
doesn't look perfect but a fully-opaque version almost completely
masked the image underneath. Should perhaps get a new image for
this, with thinner strands and no or thinner outline.

player_caught_in_net no longer calls redraw_screen - otherwise
there would be a glimpse of a web over the player before the
item on the ground both existed and was set as "stationary" to
mark it as the trapping net (for thrown nets). The screen
seems to get redrawn shortly after anyway.
Fix field initialization order warnings.

I don't get why it should even matter for POD fields.
Revert "Remove Control Teleport from Books"

This reverts commit e79a3f13542aa36d9b522c492ffb4a0caab57df5.
Don't randomly generate items under firewood.

Oklobs are allowed, sorry.
Avoid racial variants in zigsprint starting loot (rast)

The possibility of scumming for a slightly better item has been
<sunglasses> eraced.
Track who destroys an item; incur Nemelex penance for deck destruction.

The framework here could be adopted to, say, give brownie points to
Yredelemnul worshippers for destroying holy items, or other creative
item-related god conducts.

(More importantly, you can now reliably become an Unlucky Tengu.
Hooray.)
Handle destroyed spellbooks the same as destroyed decks.

Also, simplify the penance calculation for destroyed spellbooks, to
match the one for decks (and generalize it for any other
spellbook-granting gods that care about destroyed books).
Mention destroying decks as disliked by Nemelex in the "^!" screen.
Unify handling of spellbook destruction for god purposes.

This removes a hiccup wherein Sif followers destroying books would get
double penance; it also means that Trog followers destroying books will
get piety no matter how they destroy the book.
Don't drown/incinerate player in Abyss when placing vaults.

This also adjusts some of the other checks for abyssal terrain at the
player position after abyssal terrain is adjusted.

I'm unsure as to if/how this approach will cause additional problems,
but the immediate problem (#7063) should go away with this.
Web tiles for webtiles

TILE_FLAG_WEB needed implementing as flags.WEB for
webtiles to render the web overlay correctly.
Make sure you.shove() gets called properly in Abyss code.
Don't fail asserts after placing Abyss vaults.

This borrows the env.markers.activate_all() call from the normal dungeon
builder and calls it alongside other things like link_items(); these
calls are now unified in one location, _abyss_postvault_fixup().

It's possible to explore the Abyss indefinitely now per stress tests.
Rename and document short Abyssal tests, to tell them from the main one.
Don't let the Abyss stress fly.

Newnewabyss has hardly any liquids, and it doesn't let us check fpr falling
into water.
Set the Abyss bot's stats to 72 72 72.

It spends most of the time in stat death otherwise, with all the stat drain
abundant in the Abyss.  This means monsters get to move when we should use
the CPU more for exploring the Abyss (I don't disable monsters here to get
a better test coverage).