'Creates a FeatureProfile object.
Takes kwargs to the features to enable or disable. Features not
specified but that are in APP_FEATURES will be False by default.
E.g.:
>>> FeatureProfile(sms=True).to_signature()
\'400.32.1\''

def __init__(self, _default=False, **kwargs):

    super(FeatureProfile, self).__init__()
    for af in APP_FEATURES:
        key = af.lower()
        self[key] = kwargs.get(key, _default)
