Mode Runner Demo
Running a CodeMirror mode outside of the editor.
    The CodeMirror.runMode function, defined
    in lib/runmode.js takes the following arguments:
- text (string)
- The document to run through the highlighter.
- mode (mode spec)
- The mode to use (must be loaded as normal).
- output (function or DOM node)
- If this is a function, it will be called for each token with
      two arguments, the token's text and the token's style class (may
      be nullfor unstyled tokens). If it is a DOM node, the tokens will be converted tospanelements as in an editor, and inserted into the node (throughinnerHTML).
