Detects features for each set of cuboids using stfeatures.
INPUTS
DATASETS - struct array contains all behavior data in dataset, should have fields:
.IS - the N behavior clips
.IDX - length N vector of clip types
par_stfeatures - parameters for feature detection, see stfeatures
OUTPUTS
DATASETS - array of structs, will have additional fields [IS will be removed]:
.ncilps - N: number of clips
.cubcount - length N vector of cuboids counts for each clip clip
.cuboids - length N cell vector of sets of cuboids
.subs - length N cell vector of sets of locations of cuboids
See also FEATURESSM, STFEATURES