new example code into face_detector.py and added some comments.

Merge branch 'py_det_conf_and_idx' of https://github.com/jackculpepper/dlib into jackculpepper-py_det_conf_and_idx

images.

the build more robust against name conflicts from other libraries that also
statically compile libjpeg or stick incompatible versions of libjpeg's header
files into folders in the include search path.

available in python3.

make the window show itself.

for making 3d rotations.