Story 1924: Tweaks to contributions page

* Add some browser tests for contributions and the history page (which
it is based off of to ensure nothing gets broken)
* Add icon to left of username in heading
* Make heading on contributions page point to UserProfile

Change-Id: If50d45656cdb1a2f95ddb5873fee6deaa3f366e6
Merge "Story 1924: Tweaks to contributions page"