Show authoring dates rather than commit dates in commit view (BB-14058)

The authoring date exists in git for a reason. When I open a commit, I want to see when the code was written, not when the commit was last touched by a rebase.

Indeed, Mercurial, Bitbucket’s other main VCS, stores only the authoring date and not the commit date, so Bitbucket is handling its two supported VCSs very differently in this respect.

Even more confusingly, Bitbucket currently shows the author’s name rather than the commiter’s, and yet the commit date rather than the authoring date. At the very least it should be consistent.

I imagine you’re not very fond of comparisons to GitHub, but just as another point of reference, GitHub shows the author and date first and foremost, and additionally shows the committer and commit date in small print if and only if the committer is a different person.