0028044: Data Exchange - implement data structures for Saved Views

Add new root label in Document for Views.
Add new attribute to store View in XDE.
Add object and tool to process Views.
Add new Draw commands for Views.

src/XDEDRAW/XDEDRAW_Views.hxx

@@ -0,0 +1,36 @@
+// Created on: 2016-11-22
+// Created by: Irina KRYLOVA
+// Copyright (c) 2016 OPEN CASCADE SAS
+//
+// This file is part  Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms  the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text  the license and disclaimer  any warranty.
+//
+// Alternatively, this file may be used under the terms  Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _XDEDRAW_Views_HeaderFile
+#define _XDEDRAW_Views_HeaderFile
+
+#include <Standard.hxx>
+#include <Standard_DefineAlloc.hxx>
+#include <Standard_Handle.hxx>
+
+#include <Draw_Interpretor.hxx>
+
+
+//! Contains commands to work with GDTs
+class XDEDRAW_Views 
+{
+public:
+
+  DEFINE_STANDARD_ALLOC
+
+  Standard_EXPORT static void InitCommands (Draw_Interpretor& theCommands);
+};
+
+#endif // _XDEDRAW_Views_HeaderFile