Extra padding was created for a prospective -moz-focus-inner ring.
We now just size that ring the same as the content frame, inflated by its CSS
padding.
The removal of this preference was botched, all other surrounding plumbing changes appear to be working okay. The ability to use prefs to control this stylesheet might be useful in the future, so perhaps this is one of those "if it ain't broke, don't fix it" bugs where leaving well enough alone in the first place would have been the best choice.
Since these are just interpreted comments, there's 0 impact on actual code.
This removes all lines that match /* vim: set(.*)tw=80: */ with S&R -- there are
a few others scattered around which will be removed manually in a second part.