drag-action: Allow destroying the dragged actor inside ::drag-end
drag-action: Allow destroying the dragged actor inside ::drag-end

It should be possible to destroy the actor currently being dragged from
within the ::drag-end signal. In order to do this, we need to keep a
reference on the action for the duration of the emit_drag_end() function
as well as resetting the action's state inside the dispose()
implementation, to avoid trying to access cleared data.

https://bugzilla.gnome.org/show_bug.cgi?id=681814

GNOME/clutter,ebassi/clutter,GNOME/clutter,jigpu/clutter,heysion/clutter-clone,heysion/clutter-clone,jigpu/clutter,Distrotech/clutter,heysion/clutter-clone,heysion/clutter-clone,jigpu/clutter,ebassi/clutter,collects/clutter,ebassi/clutter,djdeath/clutter-android,GNOME/clutter,djdeath/clutter,djdeath/clutter,djdeath/clutter,Distrotech/clutter,ebassi/clutter,jigpu/clutter,djdeath/clutter,GNOME/clutter,collects/clutter,collects/clutter,Distrotech/clutter,Distrotech/clutter,heysion/clutter-clone,djdeath/clutter,jigpu/clutter,djdeath/clutter-android,Distrotech/clutter,djdeath/clutter-android,djdeath/clutter-android,GNOME/clutter,djdeath/clutter-android,ebassi/clutter,jigpu/clutter,Distrotech/clutter,collects/clutter,djdeath/clutter,collects/clutter