libv4l: add video processing: whitebalance and normalize

libv4l: add video processing: whitebalance and normalize

From: Hans de Goede <hdegoede@redhat.com>

As the version number shows this work is the basis for a beta release of the
0.6.x series, the big change here is the addition of video processing to libv4l
currently this only does whitebalance and normalizing (which turns out
to be useless for most cams) but the basic framework for doing video
processing, and being able to control it through fake v4l2 controls using
for example v4l2ucp is there.
The initial version of this code was written by 3 of my computer science
students: Elmar Kleijn, Sjoerd Piepenbrink and Radjnies Bhansingh.
This initial hg commit is a cleaned up and somewhat bug fixed version of
their code.

Priority: normal

Signed-off-by: Hans de Goede <hdegoede@redhat.com>