Question correct behavior for --ignore-dir and --noignore-dir combinations
Add test for MatchGroup
Integrate patch for --ignore-dir=match:...

See also GH #42
Update changelog
Work on more tests for --ignore-dir
Add stub for --ignore-file testing
Use filter facility for --ignore-dir and --noignore-dir
Remove stringification overload for Filters

This is for debugging purposes anyway, and it messes with boolification
of filters
Remove redundant check

App::Ack::Resource::Basic::new can no longer return a falsy value,
since files are opened lazily.