Comment 4 for bug 1661661

Force pushed a rebased branch on latest master to the same place as before. Included one minor tweak to the base.tt2 file... there was a missing closing bracket for the second stylesheet that was messing with the header blocks.

All the rest of the CSS changes appear to be working in my tests.

Will spend some more time looking at the way we handle the i18n choice for LTR vs. RTL. Adding a database column for that information seems easy, but getting the catalog to interpret the data from that field is the next and more interesting step.