[application] Implement a GetActions dbus method
[application] Implement a GetActions dbus method

Actions can now be queried over dbus, and will return an array of
structs representing the action attributes. This will let potential
users display a user-readable list of actions that stays up-to-date via
the ActionsChanged signal.

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