Pass args and kwargs through get_related_links.

The basic get_related_links function inside WebAPIResource was calling children
without passing in args and kwargs, which meant that any optional parameters
passed through those would get eaten.

djblets/webapi/resources.py

@@ -722,7 +722,8 @@ def get_links(self, resources=[], obj=None, request=None,
                 'href': '%s%s/' % (clean_base_href, resource.uri_name),
             }
 
-        for key, info in self.get_related_links(obj, request).iteritems():
+        for key, info in self.get_related_links(obj, request,
+                                                *args, **kwargs).iteritems():
             links[key] = {
                 'method': info['method'],
                 'href': info['href'],