Update FileSaver.js to v2015-03-04.

[ci skip]

docs/assets/js/vendor/FileSaver.js

 /* FileSaver.js
  * A saveAs() FileSaver implementation.
- * 2015-01-04
+ * 2015-03-04
  *
  * By Eli Grey, http://eligrey.com
  * License: X11/MIT
@@ -135,6 +135,10 @@ var saveAs = saveAs
 				revoke(object_url);
 				return;
 			}
+			// prepend BOM for UTF-8 XML and text/plain types
+			if (/^\s*(?:text\/(?:plain|xml)|application\/xml|\S*\/\S*\+xml)\s*;.*charset\s*=\s*utf-8/i.test(blob.type)) {
+				blob = new Blob(["\ufeff", blob], {type: blob.type});
+			}
 			// Object and web filesystem URLs have a problem saving in Google Chrome when
 			// viewed in a tab, so I force save with application/octet-stream
 			// http://code.google.com/p/chromium/issues/detail?id=91158