Officially stable and minor improvements

• It is now being used for real work so changing development status to Production/Stable.
• Minor improvements to repr and README.

Cleanup and fixes release

• Trimmed down the public interface of the module
• Improved docstrings -- using Google format as project standard
• Automatic doctest
• Linter warning fixes

First official release

Finally there is sufficient functionality and documentation for awking to be released officially to PyPI!