[doc] Mention that org-e-confluence-export is now part of upstream
      org-mode
Bring up-to-date with recent changes in org-mode's repository

  [ Bastien Guerry <bzg@altern.org> ]
   * Initial check-in with header from
  [ Nicolas Goaziou <n.goaziou@gmail.com> ]
   * Add asynchronous export support