Grammar: commented out diagram module-level definitions not recognized

[ComFreek]

The following is not recognized as valid syntax:

// diagram test := blah jmD

[Jazzpirate]

Context?
Comments are tricky, because they're delimited differently depending on where they occur...

[ComFreek]

This was top-level in a file. Top-level comments already work for theory and view declarations. So I guess it's just a missing branch in the grammar.

If you do not object, I can do all these grammar issues in a PR. But probably that takes (until they annoy me enough) or (next MMT release).