Support remote device A5-20-01 (first step)

- Add new device parameters (some just for debugging - marked with TMP_
  prefix).
- Add 4BS teach-in variant 3 (split implementation).
Set default values for unknown data on send.
Merge pull request #11 from maggu2810/rd-a52001

Remote device A5-20-01 -> it looks like good
Add some toString functions to improve logging.
Merge pull request #12 from maggu2810/teach-in-to-string

Add some toString functions to improve logging. -> OK