All right. I'll take a stab at answering my own question. What I was hoping
to do was set the base url in the response so my templates didn't need to
worry about it and could just use a real generic "step_two" action. However,
looking into it more (and duh! thinking about it), resolving relative urls is
a pure client operation - there's nothing that I can find that will allow me
to set a base url in the response header - only in the content. I've come up with the following solutions: