New commitfest app release on March 4th

The next release of the commitfest app will take place March 4th.

The user facing changes are:
1. The form for creating a commitfest entry now contains all the
commitfest entry fields, instead of redirecting to the entries edit
page after creating it.
2. When creating a commitfest entry, the author field is defaulted to yourself.
3. When creating a commitfest entry, the description (aka title) is
autofilled based on the email you select from the "Find thread" popup.
4. Add reverse sorting on the commitfest page (done by clicking twice
on a column). Implemented by Akshat Jaimini.
5. Disallow assigning others as reviewers/committers on open
commitfest entries. This is to avoid having people mess with
"bookmarks" of others. (On closed entries it's still allowed)

Please test out the current staging website[1] to give some feedback.
HTTP auth user and password are both pgtest.

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