Update Gateway example
Make battery reading more efficient
small param adjustment+fix
Update MightyBoost sketch with A0 (in place of D7)
License, add/update get/setFrequency(), & more

Update license to GPL 3.0
Add getFrequency()
Update setFrequency(freq in hz)
Add setNetwork(id)
Modify IRQ pinout for atmega32u4 (Arduino Leonardo)
Fix RX deadlocks, update examples

This is a major patch release that should address the rx deadlocks which
cause hangs in multiple nodes networks. Thread on this is here:
https://lowpowerlab.com/forum/index.php/topic,736.0.html
Also updated node/gateway examples, and wireless programming sketches.
Merge pull request #1 from LowPowerLab/master

Fetch last changes from LowPowerLab GIT