Added "View all items" and feed is selected after subscribing

![image](https://f.cloud.github.com/assets/1084729/725408/c84bd99c-e065-11e2-8043-245cfa91aff7.png)

Here's a video comparing to Google Reader: http://www.youtube.com/watch?v=FP2fdMAoKmY (sorry, about the messed up recording).

I tried to mimic the Google Reader's behavior:

* When you subscribe to a new a feed it gets automatically selected
* When the feed doesn't have any unread items, the "View all items" link is shown.
* When this link is clicked, all the items in the current feed are shown.

In google reader, all the items are shown but the global "mode" is kept after that, I tried it but it didn't work as expected, so now I just set the mode to "all items globally". I don't know it this behavior is desired but I think it is still better than none at all.

I don't know much about javascript, hope this can be of any help, if there is something wrong, please point it out, I'll be happy to fix.

Thanks.