Drop the interfaceAddr interfaces and just use a function. Cleanup
all fallout from that. Remove the use of global variables and cleanup
the tests a bit.
* Add unit tests & cnames
* more progress
* fix
* next mw dependent unit tests
* add tests for OnNXDOMAIN
* Add AAAA and ndots unit tests; fix request.NewWithQuestion
* Correct default value in README
* add CNAMEs to readme
* review
* fix autopath examples
* fix and test CNAME response order