adds profile widget in top right and makes it appear on username click instead of
/user/profile.

Removes log out link from header.

Removes ProfilePage.

There is just a TODO there at the moment, but the idea is to have the login
form, registration form, prefs, log out button and any confirmations before
logging out there.

It should probably be called something else, like ControlPanel, now to
reflect its other uses.