Fixes ticket #34.
Fixes ticket #34.

execDotVistrails():
Installs the startup file from core/resources/default_vistrails_startup into the .dotVistrails if there is none before.

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