Beacon format doesn't match LoRaWAN Regional Parameters 1.02

[terrillmoore]

Neither the EU868 nor the US915 beacon offsets match the offsets in the spec. The EU868 code looks for a one-byte CRC on the time, but the regional params now clearly require a 2-byte CRC in that case. Probably everything needs a close look, and of course there's the small matter of testing....

[terrillmoore]

This was a bug in the spec, fixed apparently in 1.0.2a. We need to review spec against code.

[terrillmoore]

See 1.0.3 rev of spec. We should use that as our reference.

[terrillmoore]

Although Class B is not yet supported, these have been updated in the big Class A certification update.

[terrillmoore]

Updated to match 1.0.3 as part of #378.