On the revision:

- Load the c.config module rather than c in openssl/tests/build/root.build.

- Canonicalize the license in the package manifests.

- Make the .map and .def files prerequisites of the libs type target and only
  on the respective OSes.

On the release:

- Use legal{} target type for legal documentation (LICENSE, AUTHORS, etc).

  Note that this requires bumping build2 version requirement to 0.13.0.