[CRIU] support for apparmor namespaces and stacked profiles

[Tycho Andersen]

Hi guys,

Here's some patches that add support for stacked apparmor profiles. This
functionality is landing in our 16.10 kernels, and should be upstreamed Soon :)

Also, patches 6-9 in this series are not really related to apparmor stacking,
but I needed them to get everything to work on Ubuntu 16.10.

Thoughts welcome!

Tycho