Bug 199360 Provide new servlet to retrieve html fragment when in reportlet mode
Currently in reportlet mode, the framesset servlet will still wrap and return all ajax viewer code. We need a new servlet to return only html fragment generated by engine. Then this fragment can be further parsed by client side according to user's requirement.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
SessionHandle sessionHandle = new DesignEngine( null )
				.newSessionHandle( ULocale.US );
		ReportDesignHandle handle = null;
		try
		{
			
			handle = sessionHandle.openDesign( reportConfigName );
			
			if ( handle != null )
			{
				String displayTextParam = null;
				Iterator configVars = handle.configVariablesIterator( );
				while ( configVars != null && configVars.hasNext( ) )
				{
					ConfigVariableHandle configVar = (ConfigVariableHandle) configVars
							.next( );
					if ( configVar != null )
					{
						String varName = configVar.getName( );
						Object varValue = configVar.getValue( );
						if ( varName == null || varValue == null )
							continue;
						String tempName = varName;
						String paramName = null;
						
						if ( varName.toLowerCase( ).startsWith(
								ParameterAccessor.PARAM_ISNULL ) )
						{
							tempName = (String) varValue;
						}