_Win32Waker doesn't use symbolic name for TCP_NODELAY and doesn't explicitly close its tcp port

[exarkun]

_Win32Waker creates a client socket and sets IPPROTO_TCP option 1 - this is probably meant to be socket.TCP_NODELAY. It should use the symbolic name.

It also creates a server port and just lets the socket fall out of scope. It should explicitly close it instead.

[exarkun]

Also, the waker creates its connection using blocking sockets. This basically only works by accident (it may also fail under extremely obscure, rare conditions, based on how many outstanding connection attempts there are on the system).

It'd probably be good to factor this socketpair(2)-like functionality into a general API where it can be re-used (lots of tests want it).