ox-taskjuggler.el: Resolve dependencies also against ID property

* ox-taskjuggler.el (org-taskjuggler-resolve-dependencies): When
resolving dependencies do not only look for matching task_id
properties but also for the standard ID property.

That way the user can make use of the standard org-id functionality to
create unique ids for a task and yanking the id in another task as a
BLOCKER.

contrib/lisp/ox-taskjuggler.el

@@ -548,7 +548,8 @@ channel."
         (setq depends
               (org-element-map tasks 'headline
                 (lambda (task)
-                  (let ((task-id (org-element-property :TASK_ID task)))
+                  (let ((task-id (or (org-element-property :TASK_ID task)
+				     (org-element-property :ID task))))
                     (and task-id (member task-id deps-ids) task)))
                 info)))
       ;; Check BLOCKER and DEPENDS properties.  If "previous-sibling"