Added comedi::subdevice::set_clock_source, set_counter_mode, and set_gate_source.
Added comedi::subdevice::set_clock_source, set_counter_mode, and
set_gate_source.

Linux-Comedi/comedilib,olsonse/comedilib,olsonse/comedilib,Linux-Comedi/comedilib,Linux-Comedi/comedilib,Linux-Comedi/comedilib,Linux-Comedi/comedilib,olsonse/comedilib,olsonse/comedilib,Linux-Comedi/comedilib,olsonse/comedilib,olsonse/comedilib