Add interface definition of ws_wayland_obj type
Add objects/wayland_obj.c
Remove ws_wayland_obj_init() -> Mustnt be exported
Add interface definition including stubs for ws_wayland_obj
Add init callback interface and stub
Add wl_object member to ws_wayland_obj
Fixup: ws_wayland_obj_new() interface
Revert "Remove ws_wayland_obj_init() -> Mustnt be exported"

This reverts commit 9990ff4d6ee762da72449e136203ce598d915c9d.
Fixup: Interface for ws_wayland_obj_init() -> get a wl_object*, too
Fixup: Stub for ws_wayland_obj_new()
Add interface for getting the wl_object out of the ws_wayland_obj type
Add stub for ws_wayland_obj_get_wl_obj()
Add implementation for ws_wayland_obj_get_wl_obj()
Add interface for getting the ID of the wl_object
Fixup: Add wayland-server.h header to source file
Add implementation of ws_wayland_obj_get_id()
Add hash callback for ws_wayland_obj type
Initialize unused callbacks to NULL
Add files for implementation of wl_surface
Add preliminary initial implementation of wl_surface