
0.1.0 initial release
 - added liquid barrels.
 - programmer art!
 - Barrel!

0.2.0 Refining release
 - added option to refine heavy/light up to petroleum gas
 - added tar
 - added composite wall
 - may need to tweak the values a bit.

0.2.1
 - removed heavy>light>petro recipes. in base now.
 - made tar more tar-like
 - new way to get tar
 - brought barrels closer in line with 0.9.1.  Crude will be the best barrels to transport unit-for-unit though.

0.2.2
 - fixed sulfuric acid recipe