Detects and reports opening and closing of a window/door.
Nexts step is to allow for external configuration (e.g. standard mode
with one reed contact versus multi-contact mode to detect tilting of a
window/door).
- send firmware information in DEVICE message
- introduced new version of VALUE message (sending UID now instead of
timestamp)
- make SENDSTATS and RECVSTATS messages also send UID instead of timestamp
