Fix wrapped nested list item edge case.

Fix wrapped nested list item edge case.

* lisp/muse-publish.el (muse-publish-markup-regexps): Remove 2300 rule,
  since it is no longer needed.  Tweak 2200 regexp to cover 2300's use
  case.
  (muse-publish-surround-text): Tweak prefix for muse-list-item-regexp.
  (muse-list-item-type): Handle the new change to muse-list-item-regexp.

* lisp/muse-regexps.el (muse-list-item-regexp): Explicitly require
  exactly one space character in front of a unnumbered or numbered list.
  This should make it easier to match every list instance, since
  definition lists can now be handled more nicely in
  muse-publish-markup-regexps.  This also has the effect of fixing a
  wrapped nested list item edge case.
git-archimport-id: mwolson@gnu.org--2006/muse--main--1.0--patch-16