Using fake timestamp in OS version make some results invisible

Using fake timestamp in OS version make some results invisible
https://bugs.webkit.org/show_bug.cgi?id=152289

Reviewed by Stephanie Lewis.

Fix various bugs after r194088.

* public/api/commits.php:
(format_commit): Include the commit order.
* public/v2/data.js:
(CommitLogs._cacheConsecutiveCommits): Sort by commit order when commit time is missing.
* tools/pull-os-versions.py:
(OSBuildFetcher._assign_order): Use integer instead of fake time for commit order.
(available_builds_from_command): Exit early when an exception is thrown.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@194093 268f45cc-cd09-0410-ab3c-d52691b4dbfc