Display bullet next to request with errors in DarkConsole.

Summary:
I always put a `phlog()` somewhere or something fails and I have hard times figuring out which request it was.

Also fix safe HTML in panel.

Test Plan: Looked at DarkConsole with error on main page, AJAX request and both.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5784