[refactor] Write and implement BPacket + small change to RPacket
[refactor] Write and implement BPacket + small change to RPacket

TheThingsNetwork/ttn,TheThingsNetwork/ttn,LoRaWanSoFa/ttn,mgranberry/ttn,jvanmalder/ttn,LoRaWanSoFa/ttn,jvanmalder/ttn,jvanmalder/ttn,TheThingsNetwork/ttn,mgranberry/ttn,mgranberry/ttn