org-element: Fix visible-only parsing

* lisp/org-element.el (org-element--parse-elements): Also parse
  visible headlines within an otherwise compacted headline.
* testing/lisp/test-org-element.el: Add test.
Merge branch 'maint'
ox: Fix default title

* lisp/ox.el (org-export--get-global-options): Properly set default
  title, i.e. when to TITLE keyword is provided.
* testing/lisp/test-ox.el: Add tests.
Merge branch 'maint'
ox: Small refactoring

* lisp/ox.el (org-export-expand-include-keyword): Avoid using `read'
  to determine file name.
Merge branch 'maint'