Build manual page from python3 ArgumentParser object
Description
Generate manual page an automatic way from ArgumentParser object, so the
manpage 1:1 corresponds to the automatically generated --help output.
The manpage generator needs to known the location of the object,
user can specify that by (a) the module name or corresponding python filename
and (b) the object name or the function name which returns the object.
There is a limited support for (deprecated) optparse objects, too.
