Saves data using util_io, but smartly constructs a filename

def save_cache(dpath, fname, cfgstr, data, ext='.cPkl', verbose=None):
    """
    Saves data using util_io, but smartly constructs a filename
    """
    fpath = _args2_fpath(dpath, fname, cfgstr, ext)
    util_io.save_data(fpath, data, verbose=verbose)
    return fpath