Qt: PropertyWidgetQT: only added usageModeItem_ to the conext menu if we have a property (inviwo would crash if you change usage mode on a processor)
Qt: PropertyWidgetQT: only added usageModeItem_ to the conext menu if we have a property (inviwo would crash if you change usage mode on a processor)

inviwo/inviwo,Sparkier/inviwo,inviwo/inviwo,Sparkier/inviwo,inviwo/inviwo,Sparkier/inviwo,inviwo/inviwo,inviwo/inviwo,Sparkier/inviwo,inviwo/inviwo,Sparkier/inviwo