Support '* foo branch' entries.
Support '* foo branch' entries.

* tools/dist/backport.pl
  (sanitize_branch): New helper.
  (parse_entry): Use new helper and recognize '* foo branch' header lines.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1148904 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion