First use experience improvements

[David Planella]

Right now, when you use the app for the first time, without an account set up:

1. A screen is shown with a button to set up an account
2. Upon pressing that button, the Online Accounts page to set up a new account is shown
3. The user sets up an Evernote account

Up until this point, everything works fine, but the part that we're missing is to go back to the app and retrieve the notes for the account that's been set up. Right now, the only way to do that is to close the app and restart it.

If there is no way to automatically go back to the calling app (Reminders in this case) once an account has been set up, perhaps we could do the following:

1. A screen is shown with a button to set up an account
2. Upon pressing that button, the Online Accounts page to set up a new account is shown
3. In the app, a new screen is shown with a "Done, fetch my notes" button, which can be used to manually refresh the list of notes once the account has been set up and the user comes back to the app
4. The user sets up an Evernote account
5. The user switches back manually to Reminders and presses the "Done, fetch my notes" button
6. Reminders looks for the new account, goes to the Notes view and refreshes it