Fixed JQuery reference when using RequireJS's dependency system

At line #110 there is a '$' referring to the JQuery instance, but it is defined only for the 'factory' function.
```js
/**
 * Plug-in for DataTables which will reorder the internal column structure by taking the column
 * from one position (iFrom) and insert it into a given point (iTo).
 *  @method  $.fn.dataTableExt.oApi.fnColReorder
 *  @param   object oSettings DataTables settings object - automatically added by DataTables!
 *  @param   int iFrom Take the column to be repositioned from this point
 *  @param   int iTo and insert it into this point
 *  @returns void
 */
$.fn.dataTableExt.oApi.fnColReorder = function ( oSettings, iFrom, iTo )
{
	....
```
Regards,
Giacomo