Request/Response + ISO-TP

[SKPunkt]

Hi,

i wanted to read out the individual cell voltages and implemented a very simple request/response mechanism. Then it got a little more ;-)
I hope it's not to big for a pull request or i can split it up a bit.

• New Service Frame Class for Request/Response Frames in packet.py
• ISO-TP Handling in cansocket.py
• New ThingSet_CAN Class in thingset_can.py
  • Automatic CBOR de-/encoding
  • Publication Data Interface
    • dict for each device or
    • publication frame rx callback
  • Request/Response Interface
    • Simple function calls with decoded retun data
      • get, post, fetch, patch
      • create/delete should also work, but not testet yet
• Adapted to new ThingSet_CAN Class in thingset_log.py
• Updated Usage Chapter to new ThingSet_CAN Class in Readme.md
• Simple Tests in test.py

[martinjaeger]

Hey @SKPunkt,

thanks a lot for this PR. I'm very sorry that I didn't respond earlier. I didn't see the PR (must have missed the email notification) and just discovered it now because I wanted to continue some development on this library.

Your improvements look great. I'll have a more detailed look and do some tests probably next week.

One question already: Is there a reason why you didn't use the existing Python ISO-TP library, but implemented it yourself?