Add Usage, expand Contributing sections in README
index now exports Server() and Client() functions.
grunt concat will now make 9pJSON.all.js
Don't pack anything in 9pJSON. 9p2000 marshaller will have to deal.
Merge branch 'master' of https://github.com/rsbohn/9pJSON

* 'master' of https://github.com/rsbohn/9pJSON:
  match package.json to the actual name "9pJSON"