A pushlog mechanism has been implemented. Pushes are logged to a hidden, orphan branch
(refs/gitblit/pushes). The pushing user is the author and committer of the push log
commit. The timestamp of the push is the timestamp of the commit. Each push log commit
consists of plain text ref files that contain the ref change type, the previous ref
id, and the new ref id. This is a very similar structure as the reflog, except it
is maintained within the repository as a branch and has user metadata.
There is also an implemented mechanism to retrieve pushlog entries from this hidden
branch, but as of yet there is no custom pushlog ui.
Step 1: collect push log info. (Done, I think).
Step 2: display push log info.