Updated charge, Invoice improvements and other minor fixes

modules/charge/classes/Model/Charge.php

@@ -10,21 +10,25 @@
  * @license    http://dev.osbill.net/license.html
  */
 class Model_Charge extends ORM_OSB {
-	// Charge doesnt use the update column
-	protected $_updated_column = FALSE;
+	protected $_belongs_to = array(
+		'account'=>array(),
+	);
+
+	protected $_nullifempty = array(
+		'attributes',
+	);
 
 	protected $_serialize_column = array(
 		'attributes',
 	);
 
-	protected $_belongs_to = array(
-		'account'=>array(),
-	);
-
 	protected $_display_filters = array(
 		'date_orig'=>array(
 			array('Config::date',array(':value')),
 		),
+		'date_charge'=>array(
+			array('Config::date',array(':value')),
+		),
 		'amount'=>array(
 			array('Currency::display',array(':value')),
 		),