More verbosity in bin/mudacl error output

[pisuke]

When running

bin/mudacl local/device_specs.json 

I get an output like this

BUILD SUCCESSFUL in 0s
2 actionable tasks: 2 up-to-date
Running regression test.
com.google.daq.orchestrator.mudacl.MudAclGenerator$ExceptionMap: 1 type errors
 java.lang.RuntimeException: While processing type bacnet_controller rule ntp-frdev
   java.lang.IllegalArgumentException: Should not include NTP ports in ACLs
Writing errors to /home/francesco/Code/pisuke/daq/mudacl/build/mud_errors.json
com.google.daq.orchestrator.mudacl.MudAclGenerator$ExpectedException: com.google.daq.orchestrator.mudacl.MudAclGenerator$ExceptionMap: 1 type errors

Eventually I figured out there was a problem file by searching for NTP in all the files inside the mud_files/ directory, but the output can be even more useful if pointing at the problematic file.