tests: add a undocumented object

Test case for bug#593282
mkdb: show object details also for mostly undocumented objects

Simplyfy the code. If there is a section entry for an object, show the object
details and the docs we have.
Fixes #593282
style: add more classes and tweak styling

Fix some bad uses of "c_punctuation". Also hide parameters for macros in toc.
Apply "c_punctuation" to () in function pointers. Drop the 'c_punctuation' from
the function doc heading.