code: function _fnGetMaxLenString( settings, colIdx )
  	{
  		var s, max=-1, maxIdx = -1;
  	
  		for ( var i=0, ien=settings.aoData.length ; i<ien ; i++ ) {
  			s = _fnGetCellData( settings, i, colIdx, 'display' )+'';
  			s = s.replace( __re_html_remove, '' );
  	
  			if ( s.length > max ) {
  				max = s.length;
  				maxIdx = i;
  			}
  		}
  	
  		return maxIdx;
  	}
docs: Get the maximum strlen for each data column
  @param {object} settings dataTables settings object
  @param {int} colIdx column of interest
  @returns {string} max string length for each column
  @memberof DataTable#oApi