enable cython highlight in notebook

IPython/html/static/notebook/js/config.js

@@ -56,6 +56,7 var IPython = (function (IPython) {
              ,'magic_python'    :{'reg':[/^%%python3?/]}
              ,'magic_shell'      :{'reg':[/^%%bash/]}
              ,'magic_r'         :{'reg':[/^%%R/]}
+             ,'magic_text/x-cython' :{'reg':[/^%%cython/]}
             },
 
         /**