[CRIU] c/r of ipv6 addresses and link-local binds

[Tycho Andersen]

Hi Pavel,

I know the feature freeze is happening now so I'm not sure what you want to do
with these patches (or really just 3 and 4, those are the interesting ones).
They're technically "bugs" since we can't c/r some LXC containers without them,
but they're basically new feature implementations as well. I don't think it's
mission critical for us to get these into 1.8, since we can get 1.9 into
xenial, but it would be nice to have.

Anyway, the series implements c/r of ipv6 addresses, and in particular passes
the "scope_id" parameter to bind(), which ipv6 expects when binding to a link
local address.

Tycho