Changed the gas buffer update priority
Gas fire pass limit now 1/4 of the set value (balances tick/pass ratio)
Flammable gases now have optimal air/fuel burn ratios
Removed biome checks for hydrogen sulfide gas generation (caused crashes)
Removed debug printout for MineshaftBuilder save/load
Changed gas pass limit default to infinite
Gas fires now burn through flammable blocks
Added smoke & fire particle effects to gas fires
Temporarily disabled opacity for debugging

BUG: TileEntityGas doesn't seem to load gas array on world reload