given a dataflashlog in the format produced by Mission Planner,
    return a datetime which says when the file was downloaded from the APM

def logpath2dt(filepath):
    """
    given a dataflashlog in the format produced by Mission Planner,
    return a datetime which says when the file was downloaded from the APM
    """
    return datetime.datetime.strptime(re.match(r'.*/(.*) .*$',filepath).groups()[0],'%Y-%m-%d %H-%M')