Make accounts nicer

[monty5811]

• [ ] Make login with Google more obvious
• [ ] Theme change password page
• [ ] Link to change password page if user signed up by email
• [ ] Send email to office email when a new user signs up (so they can approve them)
• [ ] Fix nav bar, so the cache is invalidated on user profile save (so we don't have to wait 15 minutes for the nav bar to update)
• [ ] Remove built in django-allauth messages