- tag old-vs-new tables with tbody class oldnew
- tag better, worse, unchanged rows with classes
- print one big table, to keep alignment across tables
- tag note column and don't right-align

Change-Id: Ifd3b2103e02781904f6b73eeb47b00340484caf6
Reviewed-on: https://go-review.googlesource.com/35939Reviewed-by: Quentin Smith <quentin@golang.org>