Improve timeout task cancellation

[thewhaleking]

The missed return when reconnecting caused the cancelled exception to be propagated even when reconnecting.

Also, we had to check task.cancelled() before task.result() before checking to see if the result was an exception, because calling task.result() or task.exception() on a task with a pending asyncio.CancelledError raises that exception rather than handling it.

Also improves debug logging.