Add self-links for Differential and Maniphest

Summary:
See:

https://groups.google.com/forum/?fromgroups#!topic/phabricator-dev/WolHZVVJB7k

Render the D3, T132, etc., in the title as a link instead of in grey text. Also clean up some related CSS.

Test Plan: Looked at a revision and a task.

Reviewers: btrahan, asherwin

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D2534