Allow only synthetic events with keyval 0
Allow only synthetic events with keyval 0

We allow KeyEvents with a key symbol of '0' to fall through only
if they are marked as synthetic. Otherwise we discard them without
mercy.

Synthetic events are useful to test ClutterText behaviour; in fact,
we do use them inside the test suite exactly for that reason.

heysion/clutter-clone,rkudiyarov/clutter_osx,dlespiau/clutter,ebassi/clutter,djdeath/clutter,heysion/clutter-clone,ebassi/clutter,GNOME/clutter,jigpu/clutter,djdeath/clutter-android,djdeath/clutter-android,rkudiyarov/clutter_osx,GNOME/clutter,dlespiau/clutter,nobled/clutter,heysion/clutter-clone,djdeath/clutter-android,GNOME/clutter,spatulasnout/clutter,kerrickstaley/clutter-vala,rkudiyarov/clutter_osx,djdeath/clutter,jigpu/clutter,Distrotech/clutter,ebassi/clutter,djdeath/clutter-multithreaded,kerrickstaley/clutter-vala,djdeath/clutter-android,jigpu/clutter,djdeath/clutter-multithreaded,ebassi/clutter,heysion/clutter-clone,Distrotech/clutter,Distrotech/clutter,Distrotech/clutter,spatulasnout/clutter,tardyp/clutter,jigpu/clutter,collects/clutter,djdeath/clutter-multithreaded,rkudiyarov/clutter_osx,djdeath/clutter-android,ebassi/clutter,djdeath/clutter-multithreaded,jigpu/clutter,kerrickstaley/clutter-vala,kerrickstaley/clutter-vala,spatulasnout/clutter,nobled/clutter,spatulasnout/clutter,collects/clutter,jigpu/clutter,Distrotech/clutter,heysion/clutter-clone,tardyp/clutter,tardyp/clutter,djdeath/clutter,GNOME/clutter,collects/clutter,nobled/clutter,dlespiau/clutter,djdeath/clutter,djdeath/clutter,djdeath/clutter,spatulasnout/clutter,collects/clutter,collects/clutter,Distrotech/clutter,GNOME/clutter