We introduced djblets.feedview ages ago to help provide a rendered

RSS/Atom feed. This utilized the feedparser module, accessing a URL

and rendering the results.
We don't use this in any of our projects anymore, and there are far

better methods of accomplishing these tasks. Client-side access and

rendering is usually better, and if feeds are needed server-side, it's

better for them to provide the specific implementation they need.
This change removes djblets.feedview entirely. This also means one

less dependency, which often had its own security issues and updates.

All unit tests pass.