Make the rules for combining explicitly specified docstring, autodoc one and
the one obtained by translating Doxygen comments implicit in the structure of
the code itself instead of writing complicated conditions checking them.
This results in small changes to the whitespace in the generated Python code
when using autodoc, but this makes it PEP 8-compliant, so it is the right
thing to do anyhow.
Also cache the docstring built from translated Doxygen comments. The existing
code seemed to intend to do it, but didn't, really. This helps with
performance generally speaking (-10% for a relatively big library using a lot
of Doxygen comments) and also makes debugging Doxygen translation code less
painful as it's executed only once instead of twice for each comment.
Finally, avoid putting "r", used for Python raw strings, into docstrings in C
code, it is really not needed there.
It is very useful to be able to click on the parameter types in a function
documentation to go to this parameter description, so always use hyperlink
markup for the parameters of class types, even if not all of them are
necessarily documented -- Sphinx doesn't seem to complain about links to
unknown classes.
For the parameter documentation to be really taken as such, in its entirety,
by Sphinx, it must be indented relative to the :param: tag. Do this by
appending an extra indent after every line of the output and work around the
unnecessary indent of the last line by removing the trailing whitespace.
This required updating the existing tests and removing the expected but not
present any more whitespace from them, but as trailing whitespace in the
documentation is at best insignificant (and at worst harmful) anyhow, this is
not a big price to pay for simpler translator code.
Sphinx doesn't allow sections inside the function documentation and gives tons
of SEVERE warnings for them, so while just emphasizing the "Overload" header
is not ideal, it is better than before because at least the string "Overload"
itself appears in the Sphinx-generated output.
Using C++ types in documentation for Python users is more harmful than
useless, so use Python types whenever possible and allow defining "doctype"
typemap to customize this for the user-defined types.
reST is standard Python markup, so use *...*, ``...`` and so on instead of
_..._, '...' etc.
No other changes even though the mapping of some Doxygen tags to markup used
for them seems suspicions (e.g. \var almost certainly should be the same as
\em).
Use the more or less standard :param:, :type:, :return: and :raises: in the
function/methods descriptions.
Update the output expected from the Python tests accordingly.
Update Doxygen-specific Python unit tests to work with the new indentation.
Update one of Doxygen-specific Java tests to still build with the new handling
of srcdir.
