_parsebody(): Use get_boundary() and get_type().
_parsebody(): Use get_boundary() and get_type().

    Also, add a clause to the big-if to handle message/delivery-status
    content types.  These create a message with subparts that are
    Message instances, which best represent the header blocks of this
    content type.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator