clutter_ungrab_keyboard and clutter_get_keyboard_grab, in
clutter_do_event deliver keyboard related events only to the
actor with the keyboard grab if a grab exists.
* clutter/clutter-private.h: added keyboard_grab_actor to context.
* tests/test-grab.c: added testing for testing the keyboard grab.
clutter_ungrab_pointer and clutter_get_pointer_grab, in
clutter_do_event deliver pointer related events only to the
actor with the pointer grab if a grab exists.
* clutter/clutter-private.h: added pointer_grab_actor to context.
* tests/Makefile.am:
* tests/test-grab.c: added test for testing the pointer grab.
