remove unnecessary bottom border from headlines-frame
notice style updates
make appearance of some preference panes more similar
fix jumping when clicking tree nodes

I would also suggest to turn the font-size back to 12px and padding back to 1px 0 there. Maybe only push the font-size to 14px in articles, since that's what we look at most. Everything else should visually step back.
Merge pull request #184 from levito/patch-3

fix jumping when clicking tree nodes