Option to exit on warnings #40

Many checks and special cases are being added to dzcb that log issues but ultimately ignore problems in the codeplug input files. If someone doesn't read the logs carefully, they might not notice that something was awry. Additionally, if the logs get busy and full of ignorable warnings, then it's exceedingly difficult to find actual problems that need to be addressed.

Consider replacing some debug logging with actual warnings.warn reporting and provide an option to the user to log and ignore or treat warnings as exceptions to help clean up their input files.