This fixes the pitkiln instant cooking.

If there is a fire on top of, or around the pitkiln, the pitkiln will
ignite and start the burn countdown correctly without instantly cooking
the clay items. If the pitkiln is invalid(a state between 1 straw and 7
wood), all items will get ejected and the TE will be removed.
Merge branch 'Build79' of https://github.com/Deadrik/TFCraft into custom
fix barrel-bucket interactions, allow players to fill water jugs (but not empty them) in barrels