Initial documentation batch (YUIDoc format)

This covers what is currently documented in
http://robohydra.org/docs/0.4/api/
Use startScenario, not startTest in tests
jshint <- happy
Make the tests compatible with the latest Buster.js

* Tweak the tests so they work with the latest Buster.js
* Bump the Buster.js dependency to make sure a recent-enough
  version it available
* Create a new assertion, hasEqualBody, to transparently compare
  strings with Buffer objects
* Add dependency to samsam
Add some more files to .gitignore