Adds more detailed logging to QC Post Processor

Part of OOIION-1346.

This commit doesn't patch any code, but hopefully it will allow me to
narrow down what is happening.
Adds more logging to Registration process for parsing errors

- Adds more logging to Registration process for parsing errors
- Adds handling for the edge case where the retrieved value set is
  empty.

Part of OOIION-1346 and OOIION-1390 and OOIION-1380
Merge pull request #1421 from lukecampbell/qcpp

OOIION-1346 Adds more detailed logging to QC Post Processor