Add code to robot script that uses json library to parse position/orientation message.

Also add a simple self-test function that will run at startup and can be use for debugging, etc...

1. Create a string containing valid message.
2. Parse it using the library function. (deserialize?)
3. Verify that the values in the deserialization are correct.
4. Maybe try a malformed json string and see if you can figure
out how to recover from that. (discarding message if malformed, maybe log a message?)

I believe the outline of what needs to be done is in the code comments already. Direct questions to mcolinj if you need clarification.