protocol: move sub-surfaces to Wayland

This reverts commit 2396aec684.

This exact version of the sub-surface protocol has been copied into
Wayland core. Therefore it must be removed from here to avoid build
conflicts and useless duplication.

No other changes to sub-surface protocol consumers are needed, the
identical API is now offered by libwayland-client and libwayland-server.

The commit adding sub-surfaces to Wayland is:
Author: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

    protocol: add sub-surfaces to the core

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

clients/.gitignore

@@ -27,8 +27,6 @@ weston-keyboard
 libtoytoolkit.a
 screenshooter-client-protocol.h
 screenshooter-protocol.c
-subsurface-client-protocol.h
-subsurface-protocol.c
 tablet-shell-client-protocol.h
 tablet-shell-protocol.c
 text-client-protocol.h

clients/Makefile.am

@@ -97,8 +97,6 @@ libtoytoolkit_la_SOURCES =			\
 	window.h				\
 	text-cursor-position-protocol.c		\
 	text-cursor-position-client-protocol.h	\
-	subsurface-protocol.c			\
-	subsurface-client-protocol.h		\
 	workspaces-protocol.c			\
 	workspaces-client-protocol.h
 
@@ -227,8 +225,6 @@ BUILT_SOURCES =					\
 	desktop-shell-protocol.c		\
 	tablet-shell-client-protocol.h		\
 	tablet-shell-protocol.c			\
-	subsurface-client-protocol.h		\
-	subsurface-protocol.c			\
 	workspaces-client-protocol.h		\
 	workspaces-protocol.c
 

clients/window.h

@@ -28,7 +28,6 @@
 #include <cairo.h>
 #include "../shared/config-parser.h"
 #include "../shared/zalloc.h"
-#include "subsurface-client-protocol.h"
 
 #define ARRAY_LENGTH(a) (sizeof (a) / sizeof (a)[0])