#145 Document View - the page image doesn't scroll properly

[Miro Halas]

If the document page contains many fields (I have 8)
and the preview is not covering the whole list, then
Pages tab will scroll vertically together with the
image. Once scrolled the image frame will show as very
little on the page.

I am not sure yet how should this behave so it looks
good but I didn't want to forget this.