Implement guessing for submitted-revision posting in SVN

Review Request #9413 — Created Nov. 30, 2017 and discarded — Latest diff uploaded

Information

RBTools
master

Reviewers

Added support for guessing submitted revision posting in SVN. The summary and
description of a review request are populated with the commit message from a
submitted revision in SVN.

Manual Testing done.

Added unit test

ran nosetests -v; all tests passed.