add hidden account, cart insert/delete

add hidden account support
add delete/payout buttons to carts
add backend product sales with pdf export
add frontend product sales with pdf export
add frontend ticket sales with pdf export

common/models/Account.php

@@ -96,7 +96,7 @@ class Account extends \yii\db\ActiveRecord
     static function types() {
     	return [
     			self::TYPE_ALL => Yii::t('common/account', 'Account'),
-//     			self::TYPE_VALUE_HIDDEN => Yii::t('common/account', 'Only the name is visible'),
+    			self::TYPE_VALUE_HIDDEN => Yii::t('common/account', 'Only the name is visible'),
     	];
     }