BugFix: Italian contest exporter and communication tasks (#1196)

* BugFix: Italian contest exporter and communication tasks

When the task is a communication task and it has no stubs,
exporter assumes "alone" and "std_io".
It only changes its mind to "stub" and "fifo_io" when a stub of
any language is found.

* Yaml format extended with user_io option

This option overrides the default asumption of User I/O option in
communication tasks (stdin/stdout in tasks without stubs and
fifos in tasks with stubs).

* Formatting (maximum line length)

cmscontrib/loaders/italy_yaml.py

@@ -627,10 +627,17 @@ class YamlLoader(ContestLoader, TaskLoader, UserLoader, TeamLoader):
                     num_processes = load(conf, None, "num_processes")
                     if num_processes is None:
                         num_processes = 1
+                    io_type = load(conf, None, "user_io")
+                    if io_type is not None:
+                        if io_type not in ["std_io", "fifo_io"]:
+                            logger.warning("user_io incorrect. Valid options "
+                                           "are 'std_io' and 'fifo_io'. "
+                                           "Ignored.")
+                            io_type = None
                     logger.info("Task type Communication")
                     args["task_type"] = "Communication"
                     args["task_type_parameters"] = \
-                        [num_processes, "stub", "fifo_io"]
+                        [num_processes, "alone", io_type or "std_io"]
                     digest = self.file_cacher.put_file_from_path(
                         path,
                         "Manager for task %s" % task.name)
@@ -644,6 +651,8 @@ class YamlLoader(ContestLoader, TaskLoader, UserLoader, TeamLoader):
                                 stub_name,
                                 "Stub for task %s and language %s" % (
                                     task.name, lang.name))
+                            args["task_type_parameters"] = \
+                                [num_processes, "stub", io_type or "fifo_io"]
                             args["managers"] += [
                                 Manager(
                                     "stub%s" % lang.source_extension, digest)]