Initial implementation of lava orcs.

This includes their:

* starting screen description
* starting mutations
* restricted classes/gear
* aptitudes
* orcishness (genus)
* monster version
Lava orc Beoghishness
Lava orc temperature tracking and temperature effects

Including the mutation and A! screen.
Passive heat, based on existing passive freeze, and restricted to lava orcs for now.
Prevent lava orcs from using scrolls or books when they are too hot.

Color these items as useless.
Lava orcs have innate Stoneskin (and cannot cast it otherwise).

Though they lose the effect when they are too hot. Being too hot also gives
them an ice magic dehancer and prevents them from benefiting from Statue
Form, Ice Form, Ozocubu's Armor, and Condensation Shield.
Heavily rework the lava orc temperature mechanic.
Lava orcs can swim in lava unless it is flagged as dangerous to them.

Being immersed in lava maxes temperature and prevents any decline.
Lava orcs have slow movement when cold and fast movement when hot.
Give lava orcs a heat halo that causes fire damage to nearby enemies.
Lava orcs heat up when they enter a rage and cool down when they leave one.
Change text and display of temperature effects (box drawing characters h/t kilobyte).
Speculative monster lava orc descriptions.

Contains lava orc, lava orc berserker, lava orc warrior, lava orc
elementalist, lava orc warlord, and lava orc transmuter.
Make lava orc heat resistance depend on temperature.
Lava orc tiles.
Display heat auras in tiles
Display heat auras in WebTiles too
Cap lava orc temperature change at 1 up or down per turn.

Except when berserking or entering lava. Also, some berserk fixes.
Nerf lava swimming by making entering or exiting lava take twice as long as normal actions.
No heat aura damage to friendly co-worshippers of Beogh.