Thermite Effectiveness Scaling with Volume

-The more thermite is applied to a wall, the faster it will burn
-Scales between approx 10-25 seconds
-Rwalls have a higher minimum threshold and burn time
-Applying thermite to a wall now leaves a visible stain on the wall
Added a sound effect to igniting thermite so it's not a silent stealthy move.
Thermiting walls leave admin prints
Fixes issue #2489
Fixes issue #119

Transferred all the different colours of under clothes and shoes to obj/item/clothing/under/colour/XXX and obj/item/clothing/shoes/sneakers/XXX
Added two extra options to the spawn menu of the game panel, clothing and food.
Cleanbots now spawn foam instead of gibs!

Also spans.
Viciously murders 2.1.2

It's a feature that boldly breaks the code freeze
*Corrected right/left on mob sprites for the energy gun, the taser and the disabler (fixes #3636).
Cleans up the cleanbot a little!
Merge pull request #3662 from Ikarrus/212iskill

Viciously murders 2.1.2
Ministation Compile Fix

Fixes line 196 of MiniStation.dmm to compile correctly with new code.
Merge pull request #3682 from johnsmith38/master

Ministation Compile Fix
Frequency spellfix
Merge pull request #3664 from Menshin/right_left_reversed_mob_sprites

Fixed swapped left/right sprites for some energy guns.
Merge pull request #3610 from Aranclanos/washingmachine

Washing machine fixes
Merge pull request #3557 from Ikarrus/thermitescale

Thermite Effectiveness Scaling with Volume and Wall Type
Merge pull request #3652 from GunHog/FoamBots

Emagged cleanbots now spew foam instead of spawning gibs!
Merge pull request #3685 from Jordie0608/flamboyantostrichesenjoyslowjazz

Frequency spellfix