Reduce code duplication.
Fix regex to only detect @author annotations within phpDoc comments.

The regex is however still far from perfect but the tool now does not
false report any more when being run on itself.
Make author checks case insensitive in diffs.
Rewrote everything into subclasses for parsing and all.
Drop obsolete field.
Introduce abstract base class JsonAuthorExtractor.
Add experimental patch generating feature.
Correct phpunit test dir.
Merge branch 'release/1.1.0'
Merge tag '1.1.0' into develop

Version 1.1.0
Bump version in composer.json.