[CRIU] rebased seccomp strict patchset + check thread's creds match

[Pavel Emelyanov]

Patches 1-4 applied, thanks a lot!

Let's hope the seccomp bits get into the upstream soon :) I've created
an entry in the commits tracker (http://criu.org/Upstream_kernel_commits).
Plz, ping us when the patch migrates from maintainer to Linus' tree.

About patches 5 and 6 -- can we instead of the .expectdumpfailed file in
the zdtm dir have an explicit list of blocking tests in zdtm.sh? In the
old days we used to have "blocking/" directory in the zdtm/ one with all
the tests that block checkpoint (or restore ;) ) but hopefully Anrey
wouldn't mind if rework it on the blocking list.

-- Pavel