Updates touched files' copyright

Author: alex-kulakov

Orm/Xtensive.Orm.Tests/Linq/ContainsOverKeysCollectionTest.cs

@@ -1,6 +1,6 @@
-// Copyright (C) 2013 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2013-2020 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Alexey Kulakov
 // Created:    2013.12.30
 

Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs

@@ -1,6 +1,6 @@
-// Copyright (C) 2003-2010 Xtensive LLC.
-// All rights reserved.
-// For conditions of distribution and use, see license.
+// Copyright (C) 2010-2020 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
 // Created by: Alexis Kochetov
 // Created:    2009.02.27