only publish dependencies if they haven't already been published

only publish dependencies if they haven't already been published

* planner-authz.el (planner-authz-publishing-alist): alist to track
  published pages and their dependencies
  (planner-authz-after-markup): if planner-authz-publishing-alist
  indicates this page has already been published, and here we are
  publishing it again, the alist must be stale, so we replace it with
  a single element for this page; otherwise, add an element for this page
  to the list
  (planner-authz-after-project-publish): use
  planner-authz-publishing-alist to determine which dependencies need
  publishing
  (planner-authz-republish-dependencies-maybe): add linked pages to
  planner-authz-publishing-alist as dependencies if they're not already
  there

git-archimport-id: mwolson@gnu.org--2006-planner-el/planner-el--devel--0--patch-7