Fix automatic version update.

This fixes two things:
1. Guarantee that versions are bumped up also when presubmit errors exists. Those errors originate from other CLs and should not stop the automatic versioning.
2. Calculate the last bleeding edge version when pushing to trunk based on remote branch svn/bleeding_edge and not on local branch master. The master branch is not kept up-to-date by the script.

BUG=
TBR=jarin@chromium.org

Review URL: https://codereview.chromium.org/404093002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22501 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
[Auto-roll] Bump up version to 3.28.31.0

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/404103002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22502 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/bleeding_edge' into bleeding_edge