Wizard for running first time (as opposed to upgrading)

[mailchuck]

• [ ] it should auto-create an address a give the user an option to register it for email
• [ ] it should explain to them what channels/subscriptions are
• [ ] it should point them to a list of channels/subscriptions
• [ ] it should explain how to get help

[PeterSurda]

UI framework for this: https://github.com/dimkanovikov/QLightBoxWidget