Revision history for RPi-Pin

2.3603 2017-06-28
        - bump ver of prereq WiringPi::API to 2.3612

2.3602  2017-06-24
        - added mode_alt(), allows changing any pin to any mode

2.3601  2017-05-27
        - separated this distribution from RPi::WiringPi::Pin
        - added set_interrupt(), deprecated interrupt_set()
        - added setup() routine in new() if not called elsewhere
        - hacked tests to conform to being a stand-alone distribution
