<bugfix>Autoloading a SUDS Web Service no longer produce error messages</bugfix>
<bugfix>Autoloading a SUDS Web Service no longer produce error messages</bugfix>

Also, do not print identical errors repeatedly in handle_invalid_pipeline

core/vistrail/controller.py:
VistrailController.try_to_enable_package: return the value of handleMissingSUDSWebServicePackage
VistrailController.handle_invalid_pipeline: Print identical exceprions only once

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