As for button-test, a wl_display_roundtrip is sufficient here. The
yield() between wl_test_activate_surface() and wl_test_send_key() is
also not needed, since the two requests will arrive at the server in
order, and will activate the surface first, then send a key event.
This adds a weston-test-runner for the weston test extension and
some weston test client helper methods.
Converted keyboard-test to use the new test interface, runner,
and helper methods.
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=56822
Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>