Adds __repr__() to module registry exceptions
Adds __repr__() to module registry exceptions

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