Daqhats

- Added error reporting if user passes OPTS_EXTCLOCK when starting a scan on MCC 172.
- Clarified MCC 172 documentation.

- Added support for rev 2 MCC 172 boards.

- Fixed scan bug from 1.2.0.3 for the MCC 172.

- Added support for the MCC 172.

- Fixed mismatch in error message strings in the C library.
- Clarified the address jumper settings in the documentation.

- Fixed bug in MCC 118 scan data read functions where a 16-bit variable was
used instead of 32 bits, so more than 64K samples per channel in the scan
buffer would not be read at a time.
- Fixed issue reading daqhat EEPROMs in newer versions of Raspbian Buster.
- Added information on MCC 118 OEM.
- Added daqhats_version command.
- Added firmware version history to tools README file.