admin: Lots of fixes for running the admin panel in a WSGI server. - Use new source APIs in the dashboard to open WIP files. - Fixed broken/outdated code in some views. - Fixed cases when Flask is not running at the root URL by using the `SCRIPT_NAME` variable somewhat more properly.

import os


def slashfix(path):
    if path is None:
        return None
    if isinstance(path, str):
        return path.replace('/', os.sep)
    fixed = []
    for p in path:
        fixed.append(p.replace('/', os.sep))
    return fixed