muse-latex: Make publishing of <contents> tags optional.

muse-latex: Make publishing of <contents> tags optional.

* lisp/muse-html.el (muse-html-insert-contents): Use nreverse rather than
  reverse for a minor speed boost.

* lisp/muse-latex.el (muse-latex-header, muse-latexcjk-header): Only
  insert a table of contents when muse-latex-permit-contents-tag is nil.
  (muse-latexcjk-header): Make comments do the right thing.
  (muse-latex-permit-contents-tag): New option that specifies whether we
  should take action on the <contents> tag.
  (muse-latex-finalize-buffer): If muse-latex-permit-contents-tag is
  non-nil, publish a table of contents in the place where the <contents>
  tag is.

* muse.texi (LaTeX): Bring up-to-date with new options.
git-archimport-id: mwolson@gnu.org--2006/muse--main--1.0--patch-162