[test-mx] Add two actions to test out actions
[test-mx] Add two actions to test out actions

Add a previous-tab and next-tab action to help test out dbus support.

jonnylamb/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,jonnylamb/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,jonnylamb/mx,pwithnall/mx