Add "auto Inbox" preference/capability

[tengel]

IMAP only.

Currently the UI flow is you select your account and are presented with the list of folders. You then select a folder, get the login popup (if you don't save passwords) and then are taken to the selected folder.

We should have the ability to automatically go right to the Inbox - select the account and get the login popup, then taken right to the Inbox. A menu option should then exist to take us "back" to the Folders screen to select a new one if desired.

I find that every time I use LogicMail I always go right to the Inbox first - too many clicks in the UI, we can streamline this with a login preference for auto-go-to-Inbox. The preference would basically just short-circuit the folders screen and jump right to the login/Inbox so as to impact the current code design as little as possible - clicking ESC key would go right back to the folders like it already does, same code as before.