To extend upon the `transform` feature that was added to the `tag_gen` utility by drobbins as a part of FL-9440, it would be great to have it in `release_gen` for completeness as well.
Also, to improve the usability of the transform functionality, the original tag name should be returned to the caller, including as a format variable in the `tarball` argument.
The default pattern of the `RegexMatcher` class could also be tweaked to support patchlevels and revisions, which would be particularly useful for autogenning `dev-util/android-tools` (refer to FL-9440 again for details).