Topic np signup angular

@pjanik -- I have to put this pull request in now.  There are still several things I don't like about where this is at, but I think they can be incrementally improved. The main thing bothering me is that _signup.haml is full of repetition.  I was going to extract helper methods into signup_helpers, but I had to put it down for now.  I can pick it up later I hope.  I think this is a low-risk change, but I wanted to run it by you just the same.