Wayland support

Based on the original port to Wayland by: Joel Teichroeb, Benjamin Franzke, Scott Moreau, et al.

Additional changes in this commit, done by me:

* Wayland uses the common EGL framework
* EGL can now create a desktop OpenGL context
* testgl2 loads GL functions dynamically, no need to link to libGL anymore
* Assorted fixes to the Wayland backend

Tested on the Weston Compositor (v1.0.5) that ships with Ubuntu 13.10,
running Weston under X. Tests ran: testrendercopyex (all backends), testgl2, testgles2,testintersections

configure.in

@@ -1115,6 +1115,36 @@ CheckWarnAll()
     fi
 }
 
+dnl Check for Wayland
+CheckWayland()
+{
+    AC_ARG_ENABLE(video-wayland,
+AC_HELP_STRING([--enable-video-wayland], [use Wayland video driver [[default=yes]]]),
+                  ,enable_video_wayland=yes)
+
+    if test x$enable_video = xyes -a x$enable_video_wayland = xyes; then
+        AC_PATH_PROG(PKG_CONFIG, pkg-config, no)
+        AC_MSG_CHECKING(for Wayland support)
+        video_wayland=no
+        if test x$PKG_CONFIG != xno; then
+            if $PKG_CONFIG --exists wayland-client wayland-egl wayland-cursor egl xkbcommon ; then
+                WAYLAND_CFLAGS=`$PKG_CONFIG --cflags wayland-client wayland-egl wayland-cursor egl xkbcommon`
+                WAYLAND_LIBS=`$PKG_CONFIG --libs wayland-client wayland-egl wayland-cursor egl xkbcommon`
+                video_wayland=yes
+            fi
+        fi
+        AC_MSG_RESULT($video_wayland)
+
+        if test x$video_wayland = xyes; then
+            AC_DEFINE(SDL_VIDEO_DRIVER_WAYLAND, 1, [ ])
+            SOURCES="$SOURCES $srcdir/src/video/wayland/*.c"
+            EXTRA_CFLAGS="$EXTRA_CFLAGS $WAYLAND_CFLAGS"
+            dnl FIXME do dynamic loading code here.
+            EXTRA_LDFLAGS="$EXTRA_LDFLAGS $WAYLAND_LIBS"
+            have_video=yes
+        fi
+    fi
+}
 
 dnl Find the X11 include and library directories
 CheckX11()
@@ -2449,6 +2479,7 @@ case "$host" in
         CheckNAS
         CheckSNDIO
         CheckX11
+        CheckWayland
         CheckDirectFB
         CheckFusionSound
         CheckOpenGLX11