R1:88698bec0be1

Make use of "Mnn" in Pholio more consistent

Summary:
- Drop it from crumb.
- Add it to pinboard.
- Drop it from header.
- Add it to title.

Test Plan: looked at stuff

Reviewers: chad, ljalonen

Reviewed By: ljalonen

CC: aran

Differential Revision: https://secure.phabricator.com/D5068