add functionality to pass a class to any child element, fix dt class
add functionality to pass a class to any child element, fix dt class

dita4publishers/org.dita4publishers.html5,dita4publishers/org.dita4publishers.html5,dita4publishers/org.dita4publishers.html5,dita4publishers/org.dita4publishers.html5,dita4publishers/org.dita4publishers.html5