Permit infinitely-nested sections.

Permit infinitely-nested sections.

* examples/QuickStart (Links): Use GNA link rather than johnw's site.
  (Deriving from an existing style): Mark up as a list.

* lisp/muse-colors.el (muse-colors-outline-faces-list, muse-make-faces):
  Color an additional level of headings.

* lisp/muse-docbook.el (muse-docbook-markup-strings): Add new
  section-other, section-other-end, and section-close strings.
  (muse-docbook-fixup-sections): Removed, since Muse now implements this
  through the 'section-close string.

* lisp/muse-html.el (muse-xhtml-markup-strings): Omit newline from
  'begin-underline, since this messes up paragraph handling.  Use
  <h5></h5> for 'section-other.

  (muse-html-fixup-tables): New function that sorts the table parts so
  that order is head, foot, body.  Apparently XHTML needs this, and it
  seems like a good general practice, so we do it for HTML as well.

* lisp/muse-latex.el (muse-latex-markup-strings): Use \\paragraph{} for
  'section-other.

* lisp/muse-publish.el (muse-publish-section-close): New function that
  determines where to put the section close given heading depth and
  inserts it.
  (muse-publish-markup-heading): Handle 'section-other and
  'section-other-end.  Call `muse-publish-section-close' at end of
  function.

* lisp/muse-texinfo.el (muse-texinfo-markup-strings): Use @subsubheading
  for 'section-other.
git-archimport-id: mwolson@gnu.org--2005/muse--main--1.0--patch-164