Commitfest app release on Feb 17 with many improvements

At the FOSDEM dev meeting we discussed potential improvements to the
commitfest app and how to handle deploying future changes with minimal
disruption to existing workflows. We're going to try a new approach:
announcing a new commitfest release ~2 weeks in advance, including
release notes. That way people can try out the changes on the staging
environment and raise concerns/objections. So hereby such an
announcement:

The next commitfest app release will take place on February 17 and
will contain the following user facing changes:

1. Showing CFBot status on patch and commitfest pages
2. Showing a link to the CFBot github diff on patch and commitfest pages
3. Showing total additions/deletions of the most recent patchset on
patch and commitfest pages
4. Showing additions/deletions of the first patch of the most recent
patchset on the patch page
5. Showing the version and number of patches of the most recent
patchset on the patch page
6. Canonical links for the patch page are now /patch/{patchid} instead
of /{cfid}/{patchid}
7. If you subscribed for emails or patches where you're an author, you
will now get an email when your patch needs a rebase.
8. Clicking headers will toggle sorting, instead of always enabling it
9. Allow sorting patches by name
10. Allow sorting patches by total additions/deletions (added together
for total lines changed)
11. Add ID column to commitfest page (allows sorting)
12. Allow sorting using the header of closed patches too
13. Fix dropdown direction for dropdowns at the bottom of the page
(they now drop up)
14. The previous GiHub and CirrusCI links are now integrated into the
new CFBot status row of the patch page
15. The previous GitHub checkout instructions are now integrated into
the new CFBot status row as a button that copies the commands to the
clipboard

You can try out these changes on the staging environment[1] with
pgtest:pgtest as user & password for the http auth. If you want to
make edits you need to create a new account, read-only doesn't need an
account.

[1]: https://commitfest-test.postgresql.org/