compositor-wayland: create a basic config structure to use in new init API
compositor-wayland: create a basic config structure to use in new init API

Signed-off-by: Benoit Gschwind <6d0fcc95e39ab8ccb88bafebb2075e9d5c92b713@gnu-log.net>
Reviewed-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

giucam/weston,sir-murray/weston,Gnurou/weston,giucam/weston,Gnurou/weston,krezovic/weston,sir-murray/weston,krezovic/weston