Added features_xml parser of the sound features tree on python side
Added features_xml parser of the sound features tree on python side

vmarkovtsev/veles.sound_feature_extraction,Samsung/veles.sound_feature_extraction,vmarkovtsev/veles.sound_feature_extraction,Samsung/veles.sound_feature_extraction,vmarkovtsev/veles.sound_feature_extraction,vmarkovtsev/veles.sound_feature_extraction,Samsung/veles.sound_feature_extraction,Samsung/veles.sound_feature_extraction