'Return FeatureState objects for all features in live_config.
Creates a FeatureState object for every config entry prefixed with
"feature_".
:param world - World proxy object to the app/request state.'

@staticmethod
def get_all(world):

    features = []
    for (key, config_str) in world.live_config_iteritems():
        if key.startswith('feature_'):
            feature_state = FeatureState(key[8:], world, key, config_str)
            features.append(feature_state)
    return features
