* src/widgets/modest-header-view-render.c:

* src/widgets/modest-header-view-render.c:
        * Added some implementation work to retrieve the send status of
          mails in outbox. get_status_string() obtains the proper string
          for a status, get_status_of_uid() should retrieve the current
          status trying in all send queues, the cell renderer has a
          specific path for the case of outbox.
        * As currently it does not get the proper status from the
          send queue, we set always "waiting".
* src/widgets/modest-header-view-priv.h:
        * Added an enum of the types of compact cell renderer.
* src/widgets/modest-header-view.c:
        * Pass the proper mode to the compact cell renderer (incoming,
          outgoing, outbox).

pmo-trunk-r2502