Use is_group in subworkflow dependency check
Use is_group in subworkflow dependency check

Also fixed ignored dependencies after group

VisTrails/VisTrails,minesense/VisTrails,hjanime/VisTrails,minesense/VisTrails,VisTrails/VisTrails,minesense/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,hjanime/VisTrails,minesense/VisTrails,minesense/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,hjanime/VisTrails