Fixes being able to click the grinder buttons while it's operating (ejecting beaker before grinding is finished), the grinder window is now correctly updated.
Fixes death nettle not producing pacid upon grinding, fixes novaflower not producing condensedcapsaicin (one of its reagents) upon grinding.
Renaming "inuse" var to "operating" to avoid confusion with "in_use" var
Merge pull request #6169 from phil235/DeathNettleBlendFix

Two fixes for grinder