WIP: stub out decoders for each response
WIP: stub out well behaved driver

This prototypes a well behaved driver:
  * it sends and receives messages with the pump in sequence
The example script waits for 2 beacons, then fetches a single record,
acknowledges, then disconnects.

This is a very hello-world prototype, some obvious caveats apply:
  * it is very chatty
  * poorly organized
  * incomplete, the actual records now need decoders, only the query for serial
    and model number is decoded.
  * etc...

But, it does create a bi-directional stream API with which to control the flow
of data.
make less chatty, enable reconnect to cradle

Changing the flush to skip allows the driver to reconnect to a new pump
attached to the same cradle within ~20 seconds or so.