This employs a "lazy" approach: the "format" for the credits stays
exactly as it was, i.e., perl code. Of course one may want to change
this to another format (e.g. YAML, JSON, XML; or also shell script or
AWK, like `configure.engine` uses). But I deliberately kept it simple,
to get a minimal change that is easy to verify. Any further changes to
e.g. the format can be layered atop this.