sys_un: New module.

[Collin Funk]

Here is the sys_un module as promised + typical C/C++ header checks.

I've decided to make <sys/un.h> only generate if using a Windows version
with <afunix.h>. Therefore it cannot be included unless HAVE_UNIXSOCKET
is set to 1.

Feel free to change it if you think another way would work better.

Collin

0001-sys_un-New-module.patch
Description: Text Data

0002-sys_un-Add-tests.patch
Description: Text Data

0003-sys_un-Add-C-tests.patch
Description: Text Data