Bug 167542 A parameter group isn't deleted after moving it to another parameter group through DND
Drag a parameter group and drop it to another one is a "move" operation, which cuts the source and pastes to the destination. But the source one isn't deleted in such operation while the parameters in the group are all deleted.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DNDUtil.java
*            single or multiple transfer data, every data must be an
	 *            instance of <code>DesignElementHandle</code> or
	 *            <code>DesignElement</code>
	 * @param targetObj
	 *            target elements, class type could be
	 *            <code>DesignElementHandle</code>,<code>SlotHandle</code>
	 *            or <code>ReportElementModel</code>
	 * @param position
	 *            the position will be added
	 * @param commandName
	 * @param commandType
	 *            TYPE_CUT or TYPE_COPY
	 * @return if succeeding in operating data
	 */
	protected static boolean operateHandles( Object transferData,
			Object targetObj, int position, String commandName,
			String commandType )
	{
		ModuleHandle designHandle = SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( );
		CommandStack stack = designHandle.getCommandStack( );
		try
		{
			stack.startTrans( commandName );
			CompoundCommand commands = new CompoundCommand( );
			if ( transferData instanceof StructuredSelection )
			{
				transferData = ( (StructuredSelection) transferData ).toArray( );
			}
			addCommandToCompound( transferData,