Optional query parameters:
- Repo-relative path to the file.
- Checkin version, using any unambiguous symbolic version name.
If passed a filename but no checkin then it will attempt to load that file from the most recent leaf checkin.
Once the page is loaded, files may be selected from any open leaf version. The only way to edit files from non-leaf checkins is to pass both the filename and checkin as URL parameters to the page. Users with the proper permissions will be presented with "Edit" links in various file-specific contexts for files which match the fileedit-glob, regardless of whether they refer to leaf versions or not.