Reorganized README in effort to reduce Time To Try Out

Basically, tried to think of someone saying "What is this thing? How can I set
it up and try it out?".  Thus pushed detailed config options, recommended
production set up, and design discussion lower in the doc.
Added sample loghandler

Just put it in failnozzle.loghandler as the Simplest Thing That Might Work
Removed wingu defaults from settings, and fixed up resulting test issues

I changed the defaults to be all @yourcompany.com, but then commented them out,
so that users will have to explicitly set them.

To get tests passing, I then added a settings() function within server.py, so
that default values could be used here and there.

Overall, imperfect tradeoffs, but likely good enough for now.