#1 Socket support

[Terry Nycum]

It would be great if a second 'open' usage could be added that accepted a Unix domain socket as destination. Basically, if the second argument--after 'open'--is a valid file system location, treat it as a Unix socket. If Unix sockets can be shared on a network, e.g. using Samba, then ideally this would be attempted regardless of platform. (If that's possible, then the validity of the file system location should be platform-dependent--i.e. the check shouldn't simply be for Unix directory tree syntax).