1-Wire and DS18B20 support added to Flame

I've just ported Paul Stoffregen's Arduino OneWire library to Flame, and added support for the ubiquitous Dallas Semiconductors DS18B20 1-Wire tempertature sensors.

A new TemperatureListener interface has been added, as these sensors can take a long time to get a reading (750ms at 12 bit resolution). If you don't want to use the listener interface, you can ask the device instance what it's latest reading was.

For an example on how to use it, see the Flame DS18B20 Tutorial.