#4 Support unix sockets starting with NUL in zsh/net/socket

[Jan Hudec]

Linux, and perhaps other unices, has an extra namespace for
unix-domain sockets. The socket name is allwed to start with NUL
byte (length of the name is then taken from the length argument to
bind/connect, so it must be computed exactly). Such sockets have
the advantage of being reaped automaticaly when they are closed,
so they can't stay behind after program crash.

Please add support for this kind of unix-domain sockets to the
zsh/net/socket module. A special option is needed obvisously, since
arguments can't contain NUL bytes.