wayland-server: Document wl_signal
wayland-server: Document wl_signal

tulcod/wayland,abooij/wayland,mchalupa/wayland,bitfactor/wayland,eyolfson/wayland,abooij/wayland,mchalupa/wayland,tulcod/wayland,sir-murray/wayland,sir-murray/wayland,tulcod/wayland,eyolfson/wayland,eyolfson/wayland,abooij/wayland,bitfactor/wayland,bitfactor/wayland,mchalupa/wayland,sir-murray/wayland