Add Reset Macro Channel function and set public key function

[aureleq]

Hello guys, I have added the following functions to the code:

• ResetMacroChannel => this is required before sending a new payload (actually could be done every 2 payloads with Wisol module). Base stations listen on one 200kHz macro channel, without the reset payloads won't be detected by the network as the module is hopping on the next 5 macrochannels when transmitting.
• Set Public/Private Key => this is for testing with Sigfox emulator (SNEK). It changes the AES key to sigfox public one

Also there are multiple "empty lines" additions/deletions when you look at the commit. It is due to the fact that you .ino file is using Windows style carriage return (CRLF), it is standard to use regular LF which is the default in Arduino IDE and most IDEs. If you don't want to commit those I can push a new pull request and ignore whitespaces/new lines.

Thanks :) Aurelien

[ThomasHoThinxtra]

Thank you very much for your input.