Allow training dummies to display weapons.
Special room revisions, later form buffs

Ideally, a special room has a few major dangers and a mass of thematic monsters
working together for attrition and careful play but enabling the inevitable
retreat and leaving a section of the floor consciously, naturally dangerous.
To these ends, key changes were made to currently potentially boring vaults:
 * Enable special rooms for many more layouts, lower default chance,
   simplified weights, cut off boring vaults by depth. This lets special rooms
   spawn (again) in Orc, Spider, Slime, Vaults, all non-end floors of the Hells.
 * Special rooms now have no door. This removes a few flavour concerns
   as well as autoexplore traps in shape recognition, and increases threat
   (through emphasizing how large groups of monsters "spill out").
 * Room by room buffs avoid homogenous boring masses of enemies for their depth
   and give minor rewards, alongside a lowered likelyhood of higher numbers.

On a case-by-case basis:
 * New special room type: mythical zoos, using standard high-fantasy beasts.
   They emphasize much depth-adjusting weighting and monster choice synergy.
 * Kobold rooms can have kobold demonologists at lower levels.
 * Orc rooms have a little gold, a boss orc, and get much harder faster.
 * Bee rooms are cut from late D, place in Spider with ruined walls,
   are rarer. Patrolling behaviour is removed to enable better swarming.
 * Morgue rooms have redone sets, especially noticable in Hells, and corpses
   to animate. Plus, Hells versions usually contain a staircase.
 * Jelly rooms can spawn on Lair:8, in Slime, and have a few less oozes/jellies.
 * No special rooms in Snake, they were only enabled due to boring layouts.

TODO:
 * layout_cocytus should use the spotty level vault connector in general.
 * Rooms look bad in layout(_chaotic)_city and are thus currently missing in
   in Dis. City layouts should subvault in special rooms, like in layout_roguey.
Match the name of non-green crystal to its recolouring and tile.

I think recoloured crystal sucks in general -- adds a new entity for no
gain -- but unless we paint this bikeshed green as it should be, let's
at least have names match the appearance.
Work around a gcc misdesign that nearly doubles the time of LTO compilation.

Someone had a bright idea of doing all compilation twice to placate broken
build systems:

traditional build:
.c -> .o:  parsing, compilation, assembly
.o -> exe: link

LTO -ffat-lto-objects:
.c -> .o:  parsing, compilation, assembly
.o -> exe: compilation, assembly, link

LTO -fno-fat-lto-objects:
.c -> .o:  parsing
.o -> exe: compilation, assembly, link

The design decision was to create "fat objects" to be able to silently
revert to non-LTO mode if the build system fails to pass appropriate flags
in the second stage.  Since gcc-4.7, it's possible to turn that off, but
the default is still compiling twice (why?!?!?).

With this fix, LTO builds take hardly more CPU than regular ones, although
some parts are still single-threaded.
Axe a std::
Tag the des cache with endianness and word width.

Lua stored inside is not portable between architectures.

One could allow separate caches in case someone shares $HOME between systems
of different architecture and switches them often, but I don't think I care
that much.  In the worst case, you'll get cache rebuilds.  A wee bit better
than crash on start until you "rm -rf ~/.crawl/saves/des".
Simplify a variable's scope.
Status icons for blind, might, and petrify.
Don't show blind icons for dazed monsters.
Don't show item corrosion messages out of LOS.
Don't mark honeycombs as preferred food.

They're no better than regular food for anyone.
Make the table of weapon str/dex weighting reflect _mostly_ status quo, use it.

I left intact (ie, effectively changed) bigger maces and axes (slightly
strengthier), extremes like quick blade and ogre clubs (slightly more
extremist), big polearms (glaive +1, bardiche +3).  If any of you would
prefer weapon types to have identical weighting like before, a reference
list is on https://crawl.develz.org/mantis/view.php?id=5825

Note that for melee weapons, a redundant and out of sync copy was used
instead, this table was consulted only for launchers.