Fixing issue with HK--en lookup-key creation and validation.

 Fixing subkey creation for addresses with an acceptable language specified. Also fixing validation to work properly for these addresses. This affects places like Hong Kong, which has both English and Chinese data.

Added test data and tests to expose the issue.

Also changing the build file to show output when running tests so when they hang because of a null-pointer exception this reaches the command line! Made debugging the tests much easier.
Yes, I have the TODO to think about it :) I was trying to think whether it made sense to have latin-names in these cases; theoretically yes but we don't have a real case at the moment. But I don't think it's harmful to canonicalise, and it is consistent.