* tests/ml/cmt/record.ml: fix
* code_map/model_graph_code.ml: highlights in .mli too!
* lang_ml/analyze/visual/highlight_ml.ml: moved helper function here
* tests/ml/visual/ref.ml: better display of globals vs constants
* tests/ml/visual/ref.mli: support
* lang_ml/analyze/visual/highlight_ml.ml: better support for
implicit labels