This fixes up a handful of relatively small issues with the manual: - Perforce moved the documentation for stunnel to a new article. - We weren't including the server monitoring doc in the toctrees. - Said monitoring doc had a broken link to the docker install docs. - Django has removed the `request-middleware` and `response-middleware` refs from their docs, so I reworded it to not try to link to them. - We weren't linking to the correct django-evolution doc location. - The diff commit validation resource was giving the wrong name for the relevant doc ref. Testing Done: Built docs and checked links.