fixed bug in shapewidget (could not restore opacity to 1.0)
Merge pull request #3 from pchampin/patch-2014-01-22

gui.edit.shapewidget: fixed bug in opacity de/serialization
gui.edit.shapewidget: fix property editing bug

After editing properties with double click and closing the edit dialog, the shape would remain in a "moving" state.
gui.edit.shapewidget: "Del" shortcut when a shape is selected in the list will delete it
Merge branch 'master' of github.com:oaubert/advene
Merge branch 'master' into visuallearning