Make an option to continue to show read items and a seamless flow

[GoogleCodeExporter]

Introduce an option in settings to allow read items to keep ticking over, I 
keep missing stuff as the feed will run in the background and count things as 
read, and when I go back to it, it just scrolls with the 'no more unread 
items'. 

Also, instead of scrolling a 'flat' list, have it keep rolling over, ie. as the 
last feed is rolling on to the screen, have the first feed underneath it so 
it's a seemless tick over (and continues forever if the read items are still 
shown)

Thanks! :)

Original issue reported on code.google.com by kum...@gmail.com on 29 Sep 2013 at 8:30