fix pix_opencv_surf with OpenCV 2

Signed-off-by: Antoine Villeret <antoine.villeret@gmail.com>
fix a crash in instantiation with no arg

this lay leave a bug behind...
add overview rule

this rule make an overview patch automatically

Signed-off-by: Antoine Villeret <antoine.villeret@gmail.com>
update facetracker
Merge branch 'master' of github.com:avilleret/pix_opencv

Conflicts:
	pix_opencv_surf.h