* Add `None` to type union for `subprocess.Popen.communicate` stub's `input` parameter.
* subprocess.communicate `input` annotated as `Optional[AnyStr]` for both 2.7 and 3.x; `timeout` as `Optional[float]`.
- Cursor is an Iterator of Any now, and .__iter__(..) and .__next__(..)
have been changed / made explicit to reflect this.
- .fetchall(..)/.fetchmany(..)/.fetchone(..) return (lists of) Anys
instead of tuples.
As per discussion in PR #663, the output of fetching values from the
cursor can be customized with a custom assignment to
.row_factory. Therefore the correct return type for fetching is Any and
not tuple.
python/mypy#2380 showed a discrepancy between object and FunctionType in stdlib2. The first defined __doc__ to be str, the second Optional[str]. As FunctionType depends on object, this is no longer valid.
As suggested by @gvanrossum in python/mypy#2380, all __doc__ should be considered Optional.
(Final verdict was just to remove most __doc__ attributes since it's inherited from object.)
