Since the Doxygen output changed quite a bit since the styling was adapted for
TagLib, the API documentation generated with Doxygen 1.9.1 has several problems:
- In the namespaces and classes lists, the nodes cannot be expanded,
'N' and 'C' characters are prepended to the namespaces and classes instead
of displaying icons.
- Class members are only accessible for the letter 'a'.
- No "Deprecated" sections are displayed (only the "TAGLIB_DEPRECATED"
definition in the signature).
- Some things are strangely styled (e.g. an empty box on the left of the
"Introduction" title).
Now most of the custom styling is removed to get it running again and to avoid
nasty surprises with doxygen changes.
