Group rST roles

[flaviut]

At the moment, rST roles like

:param str sender: The person sending the message
:param str recipient: The recipient of the message
:param str message_body: The body of the message
:param priority: The priority of the message, can be a number 1-5
:type priority: integer or None
:return: the message id

are translated individually. However, if the programmer had placed them here in a less logical way, like by putting the :return: in the middle of the parameters, it'd be a bit ugly and confusing.

It'd be nice if all roles were grouped together in the rendered output.