Merge changes I8e76f05d,I895b75bb,I60f94002,Ic739624d,I037c2b8d, ...

* changes:
  ChangeApi: Implement get/put topic
  Add tests for ChangeNotesParser parse failures
  CommitMessageOutputTest: Add helper methods for checking commits
  Move notedb commit message output tests to their own class
  Extract base class from ChangeNotesTest
  Factor parser class out of DraftCommentNotes
  Factor parser class out of ChangeNotes