Mini profiler now shows pending latency (I've wanted this forever) and whether or not the request was a loading request.

Test Plan:
Deployed to mini-profiler.appspot.com
Hit mini-profiler.appspot.com on both loading and non-loading requests
Clicked on mini profiler tab, then "Show More Request Info" and verified that pending ms and loading request data showed up

Reviewers: alpert

Differential Revision: http://phabricator.khanacademy.org/D1041