Bug 192789 Support to render reportlet using bookmark in frameset servlet.
Description: Support to render reportlet using bookmark in frameset servlet. At present, only run and preview servlet support __isreportlet&__bookmark to generate reportlet.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ReportEngineService.java
if ( reportDocument == null )
		{
			AxisFault fault = new AxisFault(
					BirtResources
							.getMessage( ResourceConstants.ACTION_EXCEPTION_NO_REPORT_DOCUMENT ) );
			fault.setFaultCode( new QName(
					"ReportEngineService.renderReportlet( )" ) ); 
			throw fault;
		}
		OutputStream out = os;
		if ( out == null )
			out = new ByteArrayOutputStream( );
		String servletPath = iServletPath;
		if ( servletPath == null )
			servletPath = request.getServletPath( );
		
		IRenderTask renderTask = engine.createRenderTask( reportDocument );
		
		BirtUtility.addTask( request, renderTask );
		HashMap context = new HashMap( );
		context.put( EngineConstants.APPCONTEXT_BIRT_VIEWER_HTTPSERVET_REQUEST,
				request );
		context.put( EngineConstants.APPCONTEXT_CLASSLOADER_KEY,
				ReportEngineService.class.getClassLoader( ) );
		
		context.put( EngineConstants.APPCONTEXT_CHART_RESOLUTION,
				ParameterAccessor.getDpi( request ) );
		
		ParameterAccessor.pushAppContext( context, request );
		renderTask.setAppContext( context );