Infinite scrolling support!

[tordo]

Hi!
Don't know if this is ready for mainline yet (haven't tested it in detail), but at least it appears to work.
It's an Alpha feature, and is marked as such in the menu. Anyways, you can take a look and see if you like it :)

Signed-off-by: Tord Øygard [email protected]

[tordo]

I myself have three concerns about the current implementation:

1. Correctness:
   Although I'm fairly certain, I'm not sure if all posts will actually be seen, or if something might get lost in the corner cases. It uses the same mechanism as the 'next' button
2. Scrolling performance
   The onScroll listener is called very, very often when scrolling. Ideally we'd hook this up into some onOverScroll listener, but to do that we have to subclass the ListView. Which should be very doable, but I'm feeling lazy right now.
3. UI:
   What do do with the next/prev buttons?

[shobhitg]

I think we should really have infinite scrolling (by default, not even as an option). I really despise clicking next.
Can we do this Tordo? If you would not like to revisit this, then let me know. I will borrow your changes and try make it happen.