Bug 137176 It takes unacceptable long time to render a report
Description: Get the attached report design, preview in report designer. It takes unacceptable long time to render a report, and users could not get the output finally. Even during the rending, the computer could not do anything else.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ReportEngineService.java
System.setProperty( EngineConstants.WEBAPP_CLASSPATH_KEY,
				scriptlibClassPath );
		config.setEngineHome( "" ); 
	}
	/**
	 * Get engine instance.
	 * 
	 * @return
	 */
	public static ReportEngineService getInstance( )
	{
		return instance;
	}
	/**
	 * Get engine instance.
	 * 
	 * @return engine instance
	 */
	public static void initEngineInstance( ServletConfig servletConfig )
			throws BirtException
	{
		if ( ReportEngineService.instance != null )
		{
			return;
		}
		ReportEngineService.instance = new ReportEngineService( servletConfig );
	}
	/**
	 * Get all the files under the specified folder (including all the files
	 * under sub-folders)