Let `org-read-date' respect `org-replace-disputed-keys' again

* lisp/org.el (org-read-date): Respect `org-replace-disputed-keys'.

Beginning from org-8.1, org-read-date ignores
`org-replace-disputed-keys'.  This commit restores the original
behavior.  Users who want the org-8.1 behavior should customize
`org-read-date-minibuffer-local-map' instead.

See http://thread.gmane.org/gmane.emacs.orgmode/90626/focus=91318 for
the discussion on this issue.

This commit in effect reverts a6986494a0
and e8023dde58.

TINYCHANGE

lisp/org.el

@@ -16600,8 +16600,7 @@ So these are more for recording a certain time/date."
 (defvar org-read-date-inactive)
 
 (defvar org-read-date-minibuffer-local-map
-  (let* ((org-replace-disputed-keys nil)
-	 (map (make-sparse-keymap)))
+  (let* ((map (make-sparse-keymap)))
     (set-keymap-parent map minibuffer-local-map)
     (org-defkey map (kbd ".")
                 (lambda () (interactive)