Make addToRandomInventory type safe

Better, Faster, Stronger

Closes #877
Fix canonical liquid if there isn't one. gah!
Removed isStackValidForSlot from TileBuildCraft and moved it to subclasses. Fixes #878
Made the stirling engine accept only fuel-type items
Made Combustion engines only accept Liquid containers and Ice
Fixed combustion engines not dropping its inventory when broken
Merge remote-tracking branch 'up/master'

Conflicts:
	common/buildcraft/energy/gui/GuiCombustionEngine.java