please make news intelligible to users

[Martin Pool]

It's important to communicate well about what we do.  So this is just
a reminder to try to write the news file entries in a way that will
clearly communicate the impact to users.  From 1.2:

    * ``merge --preview`` produces a diff of the changes merge would make,
      but does not actually perform the merge.  (Aaron Bentley)

    * New smart method ``Repository.get_parent_map`` for getting revision
      parent data. This returns additional parent information topologically
      adjacent to the requested data to reduce round trip latency impacts.
      (Robert Collins)

    * New smart method, ``Repository.stream_revisions_chunked``, for fetching
      revision data that streams revision data via a chunked encoding.  This
      avoids buffering large amounts of revision data on the server and on the
      client, and sends less data to the server to request the revisions.
      (Andrew Bennetts, Robert Collins, #178353)

The first is very clear, and encourages users to try the new option.
The second are not meaningful descriptions, even though the actual
features are very good.  They'd be better if you stated the benefit
first (that pulling from a bzr+ssh server is faster), and then how
it's done.

The 'Internals' section is obviously a bit of a special case.

-- 
Martin