Fix mobilito tutorial

[JeffAbrahamson]

• Simplify, user testing says we were too complicated.
• Make it the only thing visible when it happens: users get distracted looking at lower-down text, footers, etc. Probably make it modal.
• Simplify visual: it's too busy and doesn't adequately tutor.
• The only state we should maintain beyond the tutorial is a db flag that the user saw it (and when).
• We should have a tutorial event table for sending / composing reminders. That should be a separate issue, however, once this is done.