ob-core: Source blocks are case-insensitive

* lisp/ob-core.el (org-babel-map-src-blocks,
  org-babel-map-inline-src-blocks): Make sure to ignore case when
  looking for source blocks.

Reported-by: Christopher Genovese <genovese@cmu.edu>
<http://permalink.gmane.org/gmane.emacs.orgmode/93454>

lisp/ob-core.el

@@ -996,7 +996,8 @@ beg-body --------- point at the beginning of the body
 end-body --------- point at the end of the body"
   (declare (indent 1))
   (let ((tempvar (make-symbol "file")))
-    `(let* ((,tempvar ,file)
+    `(let* ((case-fold-search t)
+	    (,tempvar ,file)
 	    (visited-p (or (null ,tempvar)
 			   (get-file-buffer (expand-file-name ,tempvar))))
 	    (point (point)) to-be-removed)
@@ -1035,7 +1036,8 @@ If FILE is nil evaluate BODY forms on source blocks in current
 buffer."
   (declare (indent 1))
   (let ((tempvar (make-symbol "file")))
-    `(let* ((,tempvar ,file)
+    `(let* ((case-fold-search t)
+	    (,tempvar ,file)
 	    (visited-p (or (null ,tempvar)
 			   (get-file-buffer (expand-file-name ,tempvar))))
 	    (point (point)) to-be-removed)