text: Clean up button press handling
text: Clean up button press handling

Event handling should only apply to editable ClutterText actors, but we
also have the :selectable property to care about.

The button/touch press should position the cursor inside an editable
ClutterText; the :selectable property should be used to allow selecting
the text, either through pointer or touch dragging, via the keyboard, or
by multiple pointer clicks. If neither of these two conditions are met,
the ClutterText should just propagate the event handling further.

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