Remove String#stem
Add Identifier#in_dir convenience method
Remove mentions of "meta" from filesystem data source
Update filesystem data source to match 4.0
Document undocumented filesystem data source methods
Update raw_filename and identifier documentation
Remove outdated comment
Do not freeze identifiers (already frozen)
Merge branch 'experimental-4.x-pathlike-identifiers' into experimental-4.x
Let Rules use globs
Create Pattern class
Merge branch 'experimental-4.x-globs' into experimental-4.x