Enable the driver to receive messages from different origins.

The Davinci will send data from 8 different sbRIOs. They will report
their origin as the name of the root node in the JSON messages, eg.
{"p4-hand-name": ["roll", "pitch", "slide"]}.
The driver will handle messages of multiple origins.

Signed-off-by: Karl Damkjær Hansen <kdh@es.aau.dk>