Initial release, stable API

At long last, we have a stable API and the first major version!

API changes:

• Remove Hint from QuerySpec to simplify the library interface.
• Change Unmarshal behavior so it keeps trying on a best effort basis after encountering an error.

Other changes:

• Log more events and improve existing log messages.
• Improve documentation and add useful README.md.
• Correct minor slips in copyright documentation.