OverflowError on closed socket. repr(socket.socket) already works fine.

on closed socket. repr(socket.socket) already works fine.

reference to the overlapped object. IocpProactor._poll() now also ignores false
alarms: GetQueuedCompletionStatus() returns the overlapped but it is still
pending.

overlapped object. IocpProactor._poll() now also ignores false alarms:
GetQueuedCompletionStatus() returns the overlapped but it is still pending.

* Tulip issue #196: IocpProactor._poll() clears the reference to the
  overlapped operation when the operation is done. It would be better to clear
  the reference in a new _OverlappedFuture.set_result() method, but it cannot
  be done yet because of a weird bug.
* BaseSelectorEventLoop._write_to_self() now logs errors in debug mode.

* Tulip issue #196: IocpProactor._poll() clears the reference to the
  overlapped operation when the operation is done. It would be better to clear
  the reference in a new _OverlappedFuture.set_result() method, but it cannot
  be done yet because of a weird bug.
* BaseSelectorEventLoop._write_to_self() now logs errors in debug mode.

class name instead of hardcoded one.

out-of-tree builds.

Patch by Zachary Turner.

Patch by Clement Rouault.

* Fix _WaitHandleFuture.cancel(): return the result of the parent cancel()
  method.
* _OverlappedFuture.cancel() now clears its reference to the overlapped object.
  Make also the _OverlappedFuture.ov attribute private.
* Check if _WaitHandleFuture completed before unregistering it in the callback.
  Add also _WaitHandleFuture._poll() and repr(_WaitHandleFuture).
* _WaitHandleFuture now unregisters its wait handler if WaitForSingleObject()
  raises an exception.
* _OverlappedFuture.set_exception() now cancels the overlapped operation.

* Fix _WaitHandleFuture.cancel(): return the result of the parent cancel()
  method.
* _OverlappedFuture.cancel() now clears its reference to the overlapped object.
  Make also the _OverlappedFuture.ov attribute private.
* Check if _WaitHandleFuture completed before unregistering it in the callback.
  Add also _WaitHandleFuture._poll() and repr(_WaitHandleFuture).
* _WaitHandleFuture now unregisters its wait handler if WaitForSingleObject()
  raises an exception.
* _OverlappedFuture.set_exception() now cancels the overlapped operation.

added deprecation warnings to them.

by removing global 'demo'. Simple fix because 2.7/3.4 fix cannot merge.

by removing global 'demo'. Refactor and remove duplicate code.