Register a help handler for a root Python module
register_module_help_handler(module, handler)Name of a root Python module
Handler function: function(name, subtopic = NULL). The name
will be the fully qualfied name of a Python object (module, function, or
class). The subtopic is optional and is currently used only for methods
within classes.
The help handler is passed a fully qualfied module, class, or
function name (and optional method for classes). It should return a URL for
a help page (or "" if no help page is available).