Add missing methods and @coroutine decorators to AbstractEventLoop (#958)
Add missing methods and @coroutine decorators to AbstractEventLoop (#958)

Closes #953.

I reviewed the documentation at https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.AbstractEventLoop and added missing methods and missing @coroutine decorators.

I ran mypy on the sample file from the issue report to confirm that mypy handles the combination of @abstractmethod and @coroutine correctly.

Also fixed a number of types in this file that are annotated as Any but could be given more precise types (e.g., sockets and protocol factories).
euresti/typeshed,azag0/typeshed,li-dan/typeshed