weston: use Tizen recipe

weston: use Tizen recipe

Use weston from Tizen since it has some Tizen specific patches.

Note that weston-extraconf.inc is inspired from the weston recipe from
Poky so some configure options aren't the same as the ones found in
weston from Tizen (upstream). Setting exactly the same options as in
Tizen (upstream) ends up in weston not being started at runtime. This
issue is reported as Bug-Tizen: BTY-39.

Also create the user weston-launch inside the weston recipe instead of
the config-tizen-ivi.

Change-Id: I6b29bd62ec6abd7ab27c9362c3cbc10b0eb2d6c8
Signed-off-by: Kévin THIERRY <kevin.thierry@open.eurogiciel.org>