Socket shutdown

[millerlogic]

Hi, I need to shutdown a socket similar to #149 but I would also like to use this library's socket wrappers rather than fdwait.

Here is a proof of concept for unixsock only, millerlogic@9435397

Is this something you would consider integrating into the library for all the socket types?

Thank you for the library,
-Chris

[sustrik]

Yes, it looks good. Just send a pull request and don't forget to state that it's submitted under MIT/X11 license.