Updated test fixtures for the Syntax

I’ve just updated the test fixtures for the Fluent Syntax 1.0.

If you are implementing Fluent, please update the reference fixtures in your project.

The changes don’t affect the actual syntax as it’s specified, but it closes some gaps in testing that the parsers actually conform to the specification. This did affect the Mozilla implementations for example.

Thanks to Nickolas for having a hard look at what we specify, test, and implement. Thanks to Ola for helping me find a way to be more systematic about validating tests and specification.

… or you wait until Nickolas is done with me.

More patches to come.