Implement additional Hints for existing Language

Hi there,

there has already be a discussion with Geertjan and Petr regarding the 
options to implement additional Hints for an existing language. I need 
to add additional Hints for HTML files and the consensus was, that I 
should use the CSL API to implement a Language and add a HintProvider.

I did some basic tests but ran into the following situation:
As soon as I register a new Language XYZ which uses the mimeType 
text/html, the build-in HTML Language does not work anymore (no hints, 
no code-completion etc). I'd expect that all languages registered on a 
mimeType are used and not only one of those.

I was not able to find this use-case in the netbeans source-code and I'm 
currently lost :(
Could somebody probably provide an example of a working extension of an 
existing language or an alternative to the implementation of a complete 
new language?

Thank you very much,
Alex Muthmann