[suggestion] Fire can remove clouds of pox gas

Except when pox gas is a mission circumstance.

Fire removes pox gas, smoke grenade removes enemy fire clouds on detonation. These two changes would deepen mechanics of the game a bit which is a good thing.

Anything to make pox less annoying to play against. Rebreather is prolly the biggest reason I just default to arbi most of the time pugging havoc.