Make nested definition list items work much better.

Make nested definition list items work much better.

* lisp/muse-publish.el (muse-publish-surround-dl): Use
  `muse-forward-list-item'.  Don't pass indent and post-indent to the
  move function.
  (muse-publish-surround-text): If we are to determine the indentation,
  but have found no list items, set indent to the empty string.  If we
  are to determine indentation but have found an item, get all leading
  whitespace and set indent to it.  Never try to determine post-indent
  using the first line.  Try to contain the amount of "damage" a nested
  list item can do to wrapped list item text.

* lisp/muse-regexps.el (muse-list-item-regexp): Hone the definition list
  part so that it is easier to indicate the amount of desired initial
  whitespace.

* lisp/muse.el (muse-list-item-type): Make initial whitespace of a dl
  entry optional.
  (muse-forward-dl-term, muse-forward-dl-entry): Remove.  Functionality
  merged into `muse-forward-list-item'.
  (muse-forward-list-item-1): New function that determines whether a
  nested list item is found.
  (muse-forward-list-item): Move hairy nested list detection algorithm
  into `muse-forward-list-item-1'.  Be extra careful about terminating
  when we go past the boundary.
git-archimport-id: mwolson@gnu.org--2006/muse--main--1.0--patch-56