Don't scroll to bottom on resize

We're brave today..
Resizing the chatview (even unintentionally by hovering the topicline)
resulted in scrolling down the current view.
There might have been reasons.. i can't see them..

Fixes #821
Keep scrolled down views through resizeEvents

There's a reason for everything...
ChatView is rendered into the viewport from top to bottom.
If we don't scroll to bottom, the topmost line doesn't change and therefore
the scrollbar will move upwards on shrinking events.
So if the scrollbar was at bottom before the resize, make it stay there.
Initialize ChatView scrolled to bottom

Now that we don't scroll on every resize, ensure that we start scrolled
to bottom.
Merge pull request #77 from seezer/bug821

Don't scroll to bottom unexpectedly.

Fixes #821