Trigger a clear event on the etemplate DOMContainer when the etemplate is cleared, so app code can listen for it.

This allows a 'et2_unload' sort of processing.

etemplate/js/etemplate2.js

@@ -121,6 +121,8 @@ etemplate2.prototype.resize = function()
  */
 etemplate2.prototype.clear = function()
 {
+	$j(this.DOMContainer).trigger('clear');
+	
 	// Remove any handlers on window (resize)
 	if(this.uniqueId)
 	{