Let change log formatter squash title and bug reference. Repair wrongly indented first line in change log. Add automatic rietveld reload of commit messages to enable late corrections.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/83603002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18057 ce2b1a6d-e550-0410-aec6-3dcde31c8c00