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>

src/.gitignore

@@ -19,6 +19,3 @@ workspaces-protocol.c
 workspaces-server-protocol.h
 input-method-protocol.c
 input-method-server-protocol.h
-subsurface-server-protocol.h
-subsurface-protocol.c
-

src/Makefile.am

@@ -36,8 +36,6 @@ weston_SOURCES =				\
 	input-method-server-protocol.h		\
 	workspaces-protocol.c			\
 	workspaces-server-protocol.h		\
-	subsurface-protocol.c			\
-	subsurface-server-protocol.h		\
 	bindings.c				\
 	animation.c				\
 	noop-renderer.c				\
@@ -350,8 +348,6 @@ BUILT_SOURCES =					\
 	input-method-server-protocol.h		\
 	workspaces-server-protocol.h		\
 	workspaces-protocol.c			\
-	subsurface-server-protocol.h		\
-	subsurface-protocol.c			\
 	git-version.h
 
 CLEANFILES = $(BUILT_SOURCES)

src/compositor.c

@@ -53,7 +53,6 @@
 #endif
 
 #include "compositor.h"
-#include "subsurface-server-protocol.h"
 #include "../shared/os-compatibility.h"
 #include "git-version.h"
 #include "version.h"