More helpful panic if you call Work() before you call Ready()

Make pool clients safe for concurrent access with mutex.

Printf fixes

SUBMIT_JOB_SCHED is deprecated, worker.Immediately should be removed.

Clarify timeout option in Readme

worker.Immediately has value 2 which means the job will timeout after 2 seconds (maybe not very intuitive?). To have no timeout one has to pass the value 0 which is also constant worker.Unlimited (more intuitive)

Read all data before decoding incoming packet

This fixes the case of a large packet being received, the current code stops processing as soon as >12 bytes are received,

Bring back ability to get function name

expose job handle/uniqueId