fix preBattle tu calculation

TileEngine: include min 12 tu & energy when Mc'd.
speed up unit breathing/no bubbles undercover

the bool to switch frame updates was in the code, but didn't alter the speed
of the bubble frame updates, they move at the same speed as regular animations

bubbles should also not be drawn if the unit is under a visible roof
add comments.
add TileEngine -> blockFire bool

Map: tweak drawRankIcon
MapData: new function, blockFire()
Tile: fix my bork in ignite(), fire spreads again.
Merge branch 'master' of https://github.com/SupSuper/OpenXcom into oXc_kL

Conflicts:
	src/Battlescape/Map.cpp
	src/Savegame/BattleUnit.cpp
	src/Savegame/BattleUnit.h