Agenda: Fix bug with dimming blocked tasks when subtree is hidden.

Reported by Paul Mead.

lisp/ChangeLog

@@ -2,6 +2,8 @@
 
 	* org.el (org-block-todo-from-checkboxes): Announce that
 	checkboxes are the culprit.
+	(org-block-todo-from-children-or-siblings): Call
+	`org-up-heading-all instead' of `outline-up-heading'.
 
 	* org-agenda.el (org-agenda-show-1): Renamed from
 	`org-agenda-show'.

lisp/org.el

@@ -8695,7 +8695,7 @@ changes.  Such blocking occurs when:
       (org-back-to-heading t)
       (when (save-excursion
 	      (ignore-errors
-		(outline-up-heading 1)
+		(org-up-heading-all 1)
 		(org-entry-get (point) "ORDERED")))
 	(let* ((this-level (funcall outline-level))
 	       (current-level this-level))