integrate AutoDeleter's into pointers

Change-Id: I6c3925a7aec4d0647c76c2a03aad7b08985d7166
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3490
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

libnetwork: getifaddrs() now returns ipv6 and physical addresses

If available, getifaddrs() will now return additional entries for
different addresses of an interface. This is similiar to how NetBSD does
it.

This allows software such as libuv to construct detailed information
about network interfaces within the system.

Adrien have some concerns about getaddrinfo() wouldn't correctly exclude
IPv6 addresses after this change so a test was added to cover that.

Change-Id: I8c5d3a02b9294d746ca928a285f40344dfd6e3cb
Reviewed-on: https://review.haiku-os.org/c/874
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

libnetwork: Move from src/kits to src/system.

Properly speaking, this is part of POSIX and not of the Be-style
"kits", and so it should live in system/ alongside libroot.
No functional change intended.

Change-Id: I0fcf78a09c76e220ad4f1719d147978ef4a3bc52
Reviewed-on: https://review.haiku-os.org/726
Reviewed-by: Axel Dörfler <axeld@pinc-software.de>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>