'Import an app/filter class.
Lookup the KEY from the PasteDeploy local conf and import the
class named there. This class can then be used as an app or
filter factory.
Note we support the <module>:<class> format.
Note also that if you do e.g.
key =
value
then ConfigParser returns a value with a leading newline, so
we strip() the value before using it.'

def _import_factory(self, local_conf):

    class_name = local_conf[self.KEY].replace(':', '.').strip()
    return importutils.import_class(class_name)
