Fixes several errors raised by Doxygen 1.9.4:
- Adds escapes to quotes which caused parsing to miss a \param.
- Removes \return directives on void functions.
- Removes a deprecated Doxyfile parameter.
- Moves a nested list higher up to fix what looks like a bug in the Doxygen parser: I found no other explanation.
Tested manually on 1.9.4.
Fixes #5615 (closed)