The trouble with tweaking the ViewBox was that the amount of the
adjustment is expressed in the coordinate system of the image, not the
coordinate system of the bitmap that is being rendered. That means that
the additional space doesn’t necessarily extend to the single physical
pixel needed to resolve the issue.
Fixes#580
Seems much better, especially since the chevron gives us two clear
visual states (left vs. right). The hamburger doesn’t really have a
commonly accepted way of indicating whether the menu is currently open
or not.
