Support table.el-style tables

Support table.el-style tables

* NEWS: Mention support for table.el-style tables.

* lisp/muse-publish.el (muse-publish-markup-regexps): Move normal table
  rule to 2350.  Rule 2300 is now a regexp that matches table.el-style
  tables.
  (muse-publish-markup-functions): Add table-el entry.
  (muse-publish-table-el-table): New function that given a variant,
  publishes a table.el-style table using the table in the matched region.
  (muse-publish-markup-table-el): New function that determines whether
  the table.el-style table can be published, and what variant to use.

* lisp/muse-regexps.el (muse-tag-regexp): New regexp that matches the
  borders of table.el-style tables.

* lisp/muse-xml-common.el (muse-xml-markup-table): Make sure that the
  table has sufficient whitespace in front of it.
git-archimport-id: mwolson@gnu.org--2006/muse--main--1.0--patch-333