Always scroll to next item

Hi. Thanks for creating selfoss.

I've made a small change that personally makes it more comfortable for me to use selfoss, as a previous Google Reader user. The change is simply the removal of a few lines of code in the autoscroll function on selfoss-shortcuts.js. Basically, when moving to the next item, I want the page to scroll to the top of that item always, and not just when that item is outside the viewport.

Personally, it gives me less strain on the eyes, as my eyes can remain fixed on the item's title at the top of the page while traversing through the items.

Obviously it is your choice if you'd like to incorporate this change or not. To me it's important, I guess people have their own preferences about this, maybe you can incorporate this as a configuration option in config.ini.

Anyway, thanks a lot for selfoss, great piece of software.