R1:81f8b507fe21

Use shinier menu icons

Summary:
- Use @chad's nice gradient overlay icons.
- Show selected states.
- Use profile picture for profile item (not sure about this treatment?)
- Workflow the logout link

Test Plan: Will add screenshots.

Reviewers: alanh, btrahan, chad

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D3225