Bug 130495 Get rid of SessionHandleAdapter
Now, we use SessionHandleAdapter to keep current active report deisng. That's a bad practive for editor swith and rebuild will cuase lots of problmes. Need find way to replace it.
UI/org.eclipse.birt.report.designer.ui.lib/src/org/eclipse/birt/report/designer/ui/editors/LibraryLayoutEditorFormPage.java
IReportEditorPage
{
	private static final String ID = "BIRT.LibraryLayoutFormPage"; 
	private int index;
	private FormEditor editor;
	private Control control;
	private int staleType;
	private boolean stale;
	private ActivityStackListener commandStackListener = new ActivityStackListener( ) {
		public void stackChanged( ActivityStackEvent event )
		{
			updateStackActions( );
			getEditor( ).editorDirtyStateChanged( );
			staleType = IPageStaleType.MODEL_CHANGED;
		}
	};
	private ModuleHandle model;
	protected void configureGraphicalViewer( )
	{
		super.configureGraphicalViewer( );
		WrapperCommandStack stack = (WrapperCommandStack) getCommandStack( );