OneWire in Due

I'd like to merge this change into OneWire.

I'm current the de-facto maintainer of OneWire, but only because it was essentially abandoned when I picked it up and fixed the many bugs. If anyone else really wants the position, it's open....

Long-term, is the ODSR (presumably will work starting with 1.5.2) or CODR and SODR approach the best way?