Support for pickling functions within a class defined outside of __main__?

Cloudpickle's ability to serialize instantiated classes and their member functions is a huge advantage over cloudpickle alternatives. Unfortunately, this feature seems limited heavily to the check for `instantiated_class.__module__ == '__main__'`.

One hacky solution is to set `__module__` in the class definition:
```
class SomeFunClass(object):
__module__ = '__main__'

# Rest of the class definition
```

But this could cause problems with any code that relies on a proper value for `__module__`. Is there another solution I'm not seeing?