In addition to the changes in the previous commit, also avoid syntax
errors in the generated Python docstrings by splitting them into several
parts if there are 3 quotes in a row in the input, as it's impossible to
have them inside triple-quoted strings, generally speaking (i.e. if
there are occurrences of both """ and ''' inside the string).
Single-line Doxygen comments ending with a double quote resulted in
syntactically-invalid Python docstrings in the output, so use triple
single quotes as delimiters in this case to avoid it.