Merged cleanup
Merged radio
Fixes for radio initialisation and radio.say()
Daeonise threads to allow python to exit
Merge branch 'daemonise' into devel
Fix digitalWrite()
Get pifm radio working
Added frequency boundaries
Remove print statements
Cleaned up call to pifm
Close pifm when the process exits
Suppress error if Radio.terminate() fails
Extra time for atexit timeout
Improved Radio.play

* Plays silence after sample
* Better error handling
Notebook demonstrates current functionality