Master commit....reads analog voltage and seems to be reading pulses okay....
got one test that pulsed 140 times and it read 145 times...no leads yet....writes
analog voltage  reading ok
poll() method is fully operational. exit strategy for clean exits
during data file retrieval implemented.

The poll() call tracks 11 fds, more can easily be added if the
device tree overlays are written to free up the gpio pins. The 0th
element of the array of pollfd structs holds the file descriptor for
haltMeterReader.txt. Currently, it's buggy. Using POLLPRI for the
events field cause poll() to never return for this file, even when
it is written to. Using POLLIN, cause immediate returns from poll()
on this fd.....dunno yet.