This patch adds the Apache license (http://www.apache.org/licenses/)
as a versioned license. Only version 2.0 is added, as the others are
historical and should not be used.

I've also updated slightly the license parse test, but I'm not sure
that the instructions for running the tests are correct (I don't see
the "license parsers" test being shown when running
./test/dist/build/suite/suite).