workaround keyconfig bug Rated 5 out of 5 stars

I've recently switched from KMail to TB and I'm hoping that a quick
trick can work around a bug in keyconfig. keyconfig keys for next and
previous messages (f,b,n,p) don't work if the folder is not shown in the
folders view. So rather than adding many folders to favorites would it
be possible to add to AUF the option to show all folders and place AUF
at the top? This would be similar to KMail and over the 7 years of using
KMail it's been proven a very productive feature. Thanks for your great
work.

This review is for a previous version of the add-on (1.3).