'This is used to list the built in features available for HaarCascade feature
detection.  Just run this function as:
>>> img.listHaarFeatures()
Then use one of the file names returned as the input to the findHaarFeature()
function.  So you should get a list, more than likely you will see face.xml,
to use it then just
>>> img.findHaarFeatures(\'face.xml\')'

def listHaarFeatures(self):

    features_directory = os.path.join(LAUNCH_PATH, 'Features', 'HaarCascades')
    features = os.listdir(features_directory)
    print features
