[CMake] Improvements for cross-referencing in the documentation?

[SF Markus Elfring]

> We already have this bug filed to improve CTest and CPack documentation:
> http://public.kitware.com/Bug/view.php?id=10067

I guess that the selection of a proper documentation format is a general problem 
for all applications.
Which are your format favourites for CMake components at the moment?

Regards,
Markus