[Mpi3-hybridpm] External interfaces chapter updates

[Bronis R. de Supinski]

Pavan:

Re:
>> 2. You need to annotate your proposed changes with ticket
>> numbers. I suggest that we need separate tickets for each
>> of the major additions. Isee that ticket 217:
>>
>> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/217
>>
>> covers the helper threads proposal. We will need ticekts
>> for the shared memory extensions and endpoints.
>
> I thought the process was changing out of using tickets for the changes
> for MPI-3. If not we can update this once all the tickets have been created.

The change tracking macros include a ticket number field.
My understanding is that for simple wording changes for
things like grammatical issues on which the chapter
reaches consensus then we can use "ticket 0". For more
significant changes, like major additions, my understanding
is that they are still supposed to use a separate ticket.
However, the revised text should be in LaTex so that
we vote on it as part of the ticket.

Bill and/or Rich should confirm or correct.

Bronis