wayland: Updates client side wayland support

wayland: Updates client side wayland support

This updates Wayland support in line with upstream changes to the Wayland
API and protocol.

This update means we no longer use the Cogl stub winsys so a lot of code
that had to manually interact with EGL and implement a swap_buffers
mechanism could be removed and instead we now depend on Cogl to handle
those things for us.

This update also adds an input device manager consistent with other
clutter backends.

Note: to use the client side "wayland" clutter backend you need to have
built Cogl with --enable-wayland-egl-platform. If Cogl has been built
with support for multiple winsys backends then you should run
applications with COGL_RENDERER=EGL in the environment.

Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>