Bug 208863 Enhance BIRT jsp tag to render reportlet using bookmark.[0603]
Description: Enhance BIRT custom jsp tag to support render reportlet using bookmark. At present, user can only use reportlet attribute and instanceid value to get reportlet. But it's not easy for end-user to get instanceid value, so the more friendly way is to support like isreportlet and bookmark attributes. Thanks.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/taglib/AbstractViewerTag.java
protected void __beforeEndTag( )
	{
		super.__beforeEndTag( );
		viewer.setParameters( parameters );
		
		pageContext.setAttribute( viewer.getId( ), viewer.getId( ) );
		
		if ( viewer.isHostPage( ) )
			pageContext.setAttribute( ATTR_HOSTPAGE, "true" ); 
	}
	/**
	 * Handle use IFrame to preview report. Each IFrame should have an unique
	 * id.
	 * 
	 * @param src
	 * @param target
	 * @throws Exception
	 */
	protected void __handleIFrame( String src, String target ) throws Exception
	{
		JspWriter writer = pageContext.getOut( );
		
		String paramContainerId = "params_" + viewer.getId( ); 
		writer
				.write( "<div id=\"" + paramContainerId + "\" style='display:none'>\n" ); 
		Iterator it = viewer.getParameters( ).values( ).iterator( );
		while ( it.hasNext( ) )
		{
			ParameterField param = (ParameterField) it.next( );