New functionality for vanilla workshops


 * Still: can make alcohol from milk. This requires milk to be stored in buckets in a 0-barrel stockpile.
 * Still: can brew specific plants.
 * Tanner's Shop: produces leather scraps while tanning, which are used to make recycled leather as they pile up.
 * Tanner's Shop: has a reaction to make artificial leather by boiling cloth in oil.
 * Quern: has a specific reaction to mill Solar Caps and Changeling Ferns into paste. Solar Cap paste can be pressed with the defaul "press oil" reaction in the screw press.
 * Quern: can mill specific plants into powder.