package/python-pillow: new package

package/python-pillow: new package

This patch adds python pillow, the friendly python image library fork,
it includes a backported patch to disable configuration platfom
guessing.

Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
[Thomas:
 - Rewrap Config.in help text.
 - As suggested by Bernd Kuhls, bump the version to 3.3.0 and drop the
   patch that has been applied upstream.
 - Rework the optional dependency handling to follow what we do in most
   Buildroot packages.
 - Add licensing information.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>