<ticket>#354</ticket> <bugfix>Fix issue with renabling packages where a signal was issued twice</bugfix>
<ticket>#354</ticket>
<bugfix>Fix issue with renabling packages where a signal was issued twice</bugfix>

gui/preferences.py:
  - QPreferencesDialog.close_dialog: disconnect the signal from the
    package manager to the now-removed packages_tab



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