Another small patch to 18.02.04

We just pushed another small patch to 18.02.04. Here are the changes:

• Fixed bug which caused dwarfs to not repeat craft more than twice, and which prevented them from sharing repeated crating tasks.

• Fixed bug which sometimes caused farms not to function with the error message "This is not a farm."

• Fixed compatibility issue that was sometimes causing the game to crash while loading chunks from old saves.