ob-tangle: Expand paths for publishing

* lisp/ob-tangle.el (org-babel-tangle-file): Return expanded file name.

Reported-by:  Arun Isaac <theroarofthedragon@gmail.com>
<http://permalink.gmane.org/gmane.emacs.orgmode/101290>

lisp/ob-tangle.el

@@ -179,7 +179,7 @@ Return a list whose CAR is the tangled file name."
 	(save-window-excursion
 	  (find-file file)
 	  (setq to-be-removed (current-buffer))
-	  (org-babel-tangle nil target-file lang))
+	  (mapcar #'expand-file-name (org-babel-tangle nil target-file lang)))
       (unless visited-p
 	(kill-buffer to-be-removed)))))