make the hide-menu gesture double as an action for closing all notifications

I regularly had situations where I received a whole pile of
notifications that were hard to close. Dunst is configured to
open the notification upon click and close upon right click, but
we can't do a right click on our touchscreens, and I didn't want to
override the default left-click behaviour that might be useful.
This should hopefully solve it.

(this solution requires dbus-x11 to be installed)

Signed-off-by: Stacy Harper <contact@stacyharper.net>

scripts/core/sxmo_inputhandler.sh

@@ -134,6 +134,7 @@ if [ "$HANDLE" -ne 0 ]; then
 			;;
 		"hidemenu")
 			pkill -9 dmenu
+			dunstctl close-all
 			;;
 		"closewindow")
 			sxmo_killwindow.sh close