Bug 148755 Add tthe status to the ActivityStackEvent.
If the the event rollback, the ActivityStackEvent status should be ROLL_BACK.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/activity/ActivityStack.java
redoStack.push( record );
		record.performPostTasks( transStack );
		
		sendNotifcations( new ActivityStackEvent( this,
				ActivityStackEvent.UNDONE ) );
	}
	/**
	 * Calls redo on the ActivityRecord at the top of the redo stack, and pushes
	 * that record onto the undo stack. This method should only be called when
	 * {@link #canUndo()}returns <code>true</code>.
	 */
	public void redo( )
	{
		
		assert canRedo( );
		
		ActivityRecord record = (ActivityRecord) redoStack.pop( );
		assert record.getState( ) == ActivityRecord.UNDONE_STATE;
		record.redo( );
		record.setState( ActivityRecord.REDONE_STATE );
		
		
		
		undoStack.push( record );
		record.performPostTasks( transStack );
		
		sendNotifcations( new ActivityStackEvent( this,
				ActivityStackEvent.REDONE ) );
	}