Revert the previous commit
The mcs cascade files used by facial_features.cpp namely
haarcascade_mcs_nose.xml and haarcascade_mcs_mouth.xml have been moved
to the repo opencv_contrib/modules/face/ due to some licensing issues.
The previous commit placed them back in the opencv/data/haarcascades/
directory which is not a good idea! Any code that used the mcs cascades
will take the link to the XML files as input from the user (until a
work-around is found).