RFR: JDK-8071686 [DIO1.0.1] I2CDevice updates

[Sergey Nazarkin]

issue: https://bugs.openjdk.java.net/browse/JDK-8071686
webrev: http://cr.openjdk.java.net/~snazarki/8071686/

This is first update from the specification update set.

I2CDevice support Transactional interface optionally.  Since Linux 
doesn't fit the spec requirement its I2CDevice implementation doesn't 
inherit Transactional interface.

-- 
/Sergey