Improved error handling by returning exec status
Improved error handling by returning exec status

All RPC methods called by crowdlabs (excluding medleys methods) now
return (result, status) where status is a 1 or 0, indicating either a
successful or unsuccessful execution. This will help with error handling
on the crowdlabs webserver.

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