Add summary/description guessing for committed revs in SVN.
Review Request #9478 - Created Jan. 10, 2018 and submitted
When posting committed revisions in SVN, there are commit messages which
we can use to guess the summary and description of the resulting review
request. This change implements
get_commit_message_rawto do that.
Based on work by Graham Seaman.
- Verified that the SVN log was parsed correctly.
- Ran unit tests.