Add partial support for ipset

[corny]

Looking forward to read your comments and improve my code.

[jellonek]

Great contribution!
Only minor documentation nits.

[jellonek]

Exported name without docstring.
Please add docstrings to all names which are started with upper case, using convention described in https://blog.golang.org/godoc-documenting-go-code

[corny]

done

[vishvananda]

This is looking good. Can you please squash it down into a single commit?

[aboch]

You may want to remove these two binaries from the diffset

[corny]

You may want to remove these two binaries from the diffset

These are netlink responses. They are required by ipset_linux_test.go.

[onokonem]

hi @corny

I have a problem with this patch

$uname -a
Darwin AF6438.local 18.2.0 Darwin Kernel Version 18.2.0: Fri Oct  5 19:41:49 PDT 2018; root:xnu-4903.221.2~2/RELEASE_X86_64 x86_64

$go version
go version go1.11.2 darwin/amd64

$GOOS=linux go build ./netmanager/cmd/netmanager
# github.com/AnchorFreePartner/services/vendor/github.com/vishvananda/netlink
../../vendor/github.com/vishvananda/netlink/ipset_linux.go:211:34: undefined: unix.NFNL_SUBSYS_IPSET

any idea why?

[corny]

@onokonem You don't have the proper header files on your system.

[corny]

@vishvananda ping

[vishvananda]

@corny Thanks for updating this. Our policy is for prs to be a single commit. Can you squash this down? You can add a co-authored-by line for the original author so we don't lose their contributions.

[corny]

I squashed it