Don't use beanstalk client directly, subclass custodian/queue, or similar
to allow us to swap out the queue and stub it for testing.

Use a class factory to instantiate tests on the worker-side.

Use either a proper grammer, or use the protocol-tests when parsing.

Rewrite rsync/ssh/ftp, etc, as a subclass of tcp.rb

The HTTP/HTTPS-probe should be pure Ruby.  Patrick will give me a stub.