Fix global dynamic variables in org-table.el.

Thanks to Martyn Jago for this patch.

lisp/org-table.el

@@ -2364,7 +2364,7 @@ of the new mark."
 		       (looking-at org-table-auto-recalculate-regexp))
        (org-table-recalculate) t))
 
-(defvar modes)
+(defvar org-table-modes)
 (defsubst org-set-calc-mode (var &optional value)
   (if (stringp var)
       (setq var (assoc var '(("D" calc-angle-mode deg)
@@ -2372,10 +2372,10 @@ of the new mark."
 			     ("F" calc-prefer-frac t)
 			     ("S" calc-symbolic-mode t)))
 	    value (nth 2 var) var (nth 1 var)))
-  (if (memq var modes)
-      (setcar (cdr (memq var modes)) value)
-    (cons var (cons value modes)))
-  modes)
+  (if (memq var org-table-modes)
+      (setcar (cdr (memq var org-table-modes)) value)
+    (cons var (cons value org-table-modes)))
+  org-table-modes)
 
 (defun org-table-eval-formula (&optional arg equation
 					 suppress-align suppress-const