- Mark references to command-line switches with the bf(...) macro.

- Changed some verb(...) macros to use other yodl idioms because
  yodl inserts way too much vertical whitespace surrounding the
  item.
- Some items weren't indenting enough in the manpage, though they
  were indenting fine in the HTML version, so used some creative
  idioms to get things to render well in both.
- Got rid of some empty lines in lists.
- Made several quote(...) items also tt(...).