egl-gdl: Don't generate cogl-display.h

It's not necessary to generate cogl-display.h just for the GDL backend
and to change the inclusion of libgdl.h. We can just tweak the include
CFLAGS to put /usr/include/CE4100 in the search path when needed.

Previously this did not work because of a stay ',' at the end of the
COGL_EXTRA_CFLAGS int he configure.ac. This actually simplifies the
code, which is always good.

This also fixes out of tree builds.

https://bugzilla.gnome.org/show_bug.cgi?id=655724

Reviewed-by: Neil Roberts <neil@linux.intel.com>

.gitignore

@@ -23,7 +23,6 @@ stamp-marshal
 *.gir
 *.typelib
 /cogl/cogl-defines.h
-/cogl/cogl-display.h
 /cogl/cogl-enum-types.c
 /cogl/cogl-enum-types.h
 config.*

cogl/cogl-display.h

@@ -37,7 +37,7 @@
 G_BEGIN_DECLS
 
 #ifdef COGL_HAS_EGL_PLATFORM_GDL_SUPPORT
-#include <@COGL_CEX100_LIBGDL_PREFIX@libgdl.h>
+#include <libgdl.h>
 #endif
 
 /**

configure.ac

@@ -653,12 +653,10 @@ AS_IF([test "x$enable_gdl_egl_platform" == "xyes"],
             AC_CHECK_HEADERS(
               [CE4100/libgdl.h],
               [
-               COGL_EXTRA_CFLAGS="$COGL_EXTRA_CFLAGS -I/usr/include/CE4100",
+               COGL_EXTRA_CFLAGS="$COGL_EXTRA_CFLAGS -I/usr/include/CE4100"
-               COGL_CEX100_LIBGDL_PREFIX=CE4100/
               ],
               [AC_MSG_ERROR([libgdl.h not found])])
           ])
-        AC_SUBST([COGL_CEX100_LIBGDL_PREFIX])
 
         COGL_EXTRA_LDFLAGS="$COGL_EXTRA_LDFLAGS -lgdl"
 
@@ -956,7 +954,6 @@ cogl/Makefile
 cogl/cogl-1.0.pc
 cogl/cogl-2.0-experimental.pc
 cogl/cogl-defines.h
-cogl/cogl-display.h
 cogl-pango/Makefile
 cogl-pango/cogl-pango-1.0.pc
 cogl-pango/cogl-pango-2.0-experimental.pc