Devguide wordsmith

Jim, chapter 8 is ready.  I just sent a pull request for the whole branch since I'm not remembering precisely what you're doing with it.  If you need anything else let me know.  I am currently working on chapter 10.

Additionally, there's a comment from Rich I left in about the meaning of "snapshots".  Can you check it out?  If I need to do anything on it let me know, but I thought it was something you could easily address.

@sez11a