fixed: plugin ticket: when a session expires all files from editticket were removed

it should be removed only those new added


git-svn-id: svn://ttmath.org/publicrep/winix/trunk@798 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/plugindata.h

@@ -2,7 +2,7 @@
  * This file is a part of Winix
  * and is not publicly distributed
  * 
- * Copyright (c) 2008-2010, Tomasz Sowa
+ * Copyright (c) 2008-2012, Tomasz Sowa
  * All rights reserved.
  * 
  */
@@ -19,6 +19,13 @@
 struct PluginDataBase
 {
 	virtual ~PluginDataBase() {}
+
+	/*
+		when deleting sessions we first call Clear() method
+		consequently the destructor has nothing to do
+		(and it doesn not throw an exception)
+	*/
+	virtual void Clear() {}
 };