UART adaptations for modern Raspbian (#56)
UART adaptations for modern Raspbian (#56)

- Modernized tty naming ("serial0" / "serial1")
- Added 2400 / 4800 speeds
- refactored SysFSUART init() to take a list of devices to try in order of preference (first successful wins)

uraimo/SwiftyGPIO,stephanmantler/SwiftyGPIO,uraimo/SwiftyGPIO,stephanmantler/SwiftyGPIO