SYSINT-5891 Fix Jira comment in case when special chars in commit message
SYSINT-5899 Go back to using git diff --name-status for file list

Since git log --name-status gives NO files on a merge commit
Use --first-parent to determine which commits to compare so
we get a better list.
SYSINT-5896 Exclude duplicate commits from pre/post-receive

Figure out which commits are new in this push by directly excluding
not only previous commints on all existing branches but also commits
before the base commit on changed branches.

Add branches_changed to pre/post receive hooks.
Take out error for empty commit list from add_comment (we could have an empty commit list
if the only thing pushed did a fast forward merge)
SYSINT-5896 fix rev-list not to be ambiguous
SYSINT-5928 Handle duplicate ticket in same commit SYSINT-5928