Update JobTest to call transformForRead on pipes.

I want JobTest to actually apply a transformForRead on it's sources. It doesn't seem to do this now in the CascadingLocal Test mode and that's foiling one of my job tests.

I haven't figured it out yet, but wanted to start a discussion on how to do this. My first attempt doesn't quite work, but it's a rough idea of what I'd like to be able to do. Thoughts?