title: Mapping of <ctrl-#> characters
body: <p>I've been trying to map certain sequences to parenthesis/bracket completion without any success.  I've been trying the following commands to map certain control sequences but they don't seem to work.  Does anyone know what I'm doing wrong here?  </p>
  
  <p>:imap &lt;ctrl-9&gt; ( )hha <br/>
  :imap &lt;ctrl-(&gt; ( )hha <br/></p>