Expected behavior

Currently AF_UNIX support in poco just checks for POCO_OS_FAMILY_UNIX

However, recent versions of windows also have AF_UNIX sockets

Actual behavior

The #Define should instead check if the feature described by https://devblogs.microsoft.com/commandline/af_unix-comes-to-windows/ is supported.

Steps to reproduce the problem

Try to build an app that uses an AF_UNIX address. Should work on supported windows versions.

POCO version

1.9.2

Compiler and version

Operating system and version

Windows 10 April 2018 update

Other relevant information

#4208