Revert "Initial commit of updated IPv6"

[rfm]

Reverts #307
Oops ...I was wrong to do that.

[rfm]

This change introduces a lot of compiler warnings, and I wonder if it actually does anything useful; the original code already has struct socket_any which is a union containing sockaddr_in6 (the IPV6 socket address) and is therefore both correctly aligned and correctly sized.

[gcasa]

@RoyalStewart90 Can you address the questions @rfm has raised?

[rfm]

I reverted that and added the bit that appears to be functional in Source/win32/NSStream.m
When we can't create IPV4 streams, try to create IPV6:

if (!ins)
{
#if defined(PF_INET6)
ins = AUTORELEASE([[GSInet6InputStream alloc]
initToAddr: address port: port]);
outs = AUTORELEASE([[GSInet6OutputStream alloc]
initToAddr: address port: port]);
#endif
}