add lock for part.json access (complete last commit)
add lock for part.json access (complete last commit)

wgerlach/Shock,teharrison/Shock,teharrison/Shock,MG-RAST/Shock,wgerlach/Shock,wgerlach/Shock,teharrison/Shock,wgerlach/Shock,wgerlach/Shock,teharrison/Shock,MG-RAST/Shock,teharrison/Shock,teharrison/Shock,MG-RAST/Shock,MG-RAST/Shock,MG-RAST/Shock