* lisp/org-element.el (org-element-item-parser,
org-element-plain-list-parser): Make sure that the element ends at
the beginning of a line if possible.
(org-element-at-point): Return expected element when point is at an
element's end or at its contents' end.
* testing/lisp/test-org-element.el: Add test.
* testing/lisp/test-org.el: Add test.