CSS reorganization and print style updates

CSS reorganization and print style updates

* muse <src> blocks now use the emacs face name as the CSS class of
  marked up regions
* Printed code is now acceptably readable and marked up to look
  tolerable when printed by my laserjet
* Reorganized the CSS rules to make things a bit easier to
  read...
* Lightened a few box backgrounds when printing
* Reduced or removed borders on all boxes when printing
* Moved the contents box to the left side of the page when printing
* Added pagination hints that result in much nicer printed output when
  using a WebKit or KHTML based browser. Alas, Mozilla still has no
  support for such things and tends to place headings at the bottom of
  pages and other horrible things.
* Cap the width of images when printing to prevent weird scaling and
  clipping issues