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
if ( stack != null )
		{
			stack.addCommandStackListener( getCommandStackListener( ) );
		}
	}
	/**
	 * returns command stack listener.
	 */
	public ActivityStackListener getCommandStackListener( )
	{
		return commandStackListener;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.forms.editor.IFormPage#initialize(org.eclipse.ui.forms.editor.FormEditor)
	 */
	public void initialize( FormEditor editor )
	{
		this.editor = editor;
	}
	public FormEditor getEditor( )
	{
		return editor;
	}
	public void init( IEditorSite site, IEditorInput input )
			throws PartInitException
	{
		super.init( site, input );
		initialize( (FormEditor)((MultiPageEditorSite)site).getMultiPageEditor() );