Fix crash, UI_WALLCOUNT was too large
TPT++ jacob1 12f00db2: loop edge mode from jacob1's mod (also works with stickmen)
TPT++ jacksonmj f7b53d02: Prevent fast particles from skipping over DESTROYALL wall
TPT++ jacksonmj 57409b0b: Change order in which particles are created by the rectangle and brush tools

to make liquid movement look less weird in normal gravity
TPT++ jacksonmj 9e7ead9b: Change melting point for snow with wrong ctype back to 273.15
TPT++ jacksonmj 66a530f5: FRZZ and FRZW changes/fixes

Fix FRZW low temperature transition (accidentally turned into a high temperature transition in b661418d).
FRZZ now melts into FRZW, so that single pixels "form ice that always cools" as in FRZZ description.
ICE update function: was meant to be checking not setting parts[i].ctype. However, turning FRZZ into self-cooling ice seems a logical thing to do, so set ctype of parts[r>>8].ctype, and make all types of ice cause this reaction (not just ICE(FRZW) as was apparently the original intention of the ctype check).
TPT++ jacksonmj 829e2cca,1eeed277: Flatter surface when liquids solidify

Previously they were moving like gases (as solids would move if they didn't have Loss=0. Since the particle has just turned into a solid, Loss=0 does not get applied to it before it moves).
TPT++ jacob1 a31f4df0: allow drawing METL/PSCN/INST ctype on CRAY
TPT++ jacob1 8233b288: Change GRVT flammability to 0