Removes zip/unzip executables requirement
Removes zip/unzip executables requirement

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