compositor_fini destroys the display, but it is an error to destroy it
before e.g. wlr_seat that references it.
This lets us order destroy calls properly, following first-in-last-out
logic.
Also:
- rename wlr_xdg_shell_v6_init to create as that is what it does
- free wlr_xdg_shell on failure to create wl_global, the struct
is not initialized enough to call destroy at that point
The surface frame callback lets a window know when it is a good time to show the
next frame if it is animating. In particular, this callback is used by
weston-simple-shm to throttle drawing.
Implement surface_attach method. This is called when a client attaches an shm
buffer with wl_surface_attach().
Implement the GLES2 interface for attaching shm buffers. This creates an opengl
texture with the shm buffer contents for the surface.
This commit also includes some working code to render the surfaces onto the
screen for demonstration purposes.
Add the wayland surface interface to the example compositor.
Implement the create_surface method to create a new wlr surface from the
wayland surface and add the interface.
