code: function _fnCallbackReg( oSettings, sStore, fn, sName )
  		{
  			if ( fn )
  			{
  				oSettings[sStore].push( {
  					"fn": fn,
  					"sName": sName
  				} );
  			}
  		}
docs: Register a callback function. Easily allows a callback function to be added to
  an array store of callback functions that can then all be called together.
  @param {object} oSettings dataTables settings object
  @param {string} sStore Name of the array storeage for the callbacks in oSettings
  @param {function} fn Function to be called back
  @param {string) sName Identifying name for the callback (i.e. a label)
  @memberof DataTable#oApi