Rename src/ to libweston/

This clarifies what is supposed to be the libweston code.

v2: screen-share.c is already in compositor/ instead.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Yong Bakos <ybakos@humanoriented.com>
Acked-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Tested-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Tested-by: Benoit Gschwind <gschwind@gnu-log.net>
Acked-by: Benoit Gschwind <gschwind@gnu-log.net>
[Pekka: rebased]

diff --git a/clients/cliptest.c b/clients/cliptest.c
index d0f4e3e..57aefda 100644
--- a/clients/cliptest.c
+++ b/clients/cliptest.c
@@ -49,7 +49,7 @@
 #include <linux/input.h>
 #include <wayland-client.h>
 
-#include "src/vertex-clipping.h"
+#include "libweston/vertex-clipping.h"
 #include "shared/xalloc.h"
 #include "window.h"