In some cases, applications (or actually, wayland compositors)
don't have the required permissions to access evdev directly, but
can do so with an external helper like weston-launch.
Allow them to do so with a custom callback that replaces the regular
open() path.
https://bugzilla.gnome.org/show_bug.cgi?id=704269
Clutter applications using evdev are typically fullscreen applications
associated with a single virtual termainal. When switching away from
the applications associated tty then Clutter should stop managing all
evdev devices and re-probe for devices when the application regains
focus by switching back to the tty. To facilitate this, this patch
adds clutter_evdev_release_devices() and clutter_evdev_reclaim_devices()
functions.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
