Changes for version 0.21
- Switched from FILTER_ONLY to FILTER due to issues with Text:::Balanced. Ultimately, this leads to more robust code (and slightly faster, too).
- Allow private subs and methods to be "signified"
- Fixed odd corner case where "substr" could confused filter if used with parens and embedded in an "if" statement. Thanks to Jerry Sievert for the report.
- Eliminated useless INIT block.
- Sub::Signatures - Use proper signatures for subroutines, including dispatching.