Removed widget from self._functions when the users remove a method
Removed widget from self._functions when the users remove a method

VisTrails/VisTrails,VisTrails/VisTrails,celiafish/VisTrails,hjanime/VisTrails,minesense/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,celiafish/VisTrails,hjanime/VisTrails,Nikea/VisTrails,minesense/VisTrails,minesense/VisTrails,celiafish/VisTrails,minesense/VisTrails,celiafish/VisTrails,Nikea/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,minesense/VisTrails,Nikea/VisTrails,hjanime/VisTrails,Nikea/VisTrails