Rework the sequence of GPIO registers in stm32l0_gpio_pin_configure t…

…o avoid suprious edges

Add Gnat variant

Add FskRadio / LoRaRadio libraries

Handle the case where somebody changes the time/date while a recurrin…

…g alarm is active in the RTC class

Rework RTC calendar to use a elapsed seconds offset (BKPx); this way …

…RTC once started does not have to be modified

Use a S11 value for subsecond correction throu PPS (BKPx)

Use RTC for millis() over Systick

Add LSE calibration via TCXO for CMWX1ZZABZ (via DIO1)

Add PPS tracking for GNSS to facility RTC phase correction

Update to OpenOCD v0.10.0-8-20180512

Parse DevAddr properly as MSB first in the LoRaWAN class

Update plaeform.txt to reflect the proper platform name

Update plaeform.txt to reflect the proper platform name

Update README.md to reflect the json file download method