-privileged support for docker build

[paulczar]

I've been doing some crazy stuff with docker inside docker and it would be awesome if I could get the -privileged -lxc-conf="aa_profile=unconfined" commands supported in docker build so that I can do docker actions in scripts as part of the build process.

[unclejack]

@paulczar Hello! Could you discuss about this on issue #1916, please? That issue is the right place to discuss about -privileged support for docker build.

[sedwards]

This is needed for installing the older JDK 1.6 packages under CentOS as its RPMs attempt to register is binmft_misc which fails without running under --privileged.

Dockerbuild is a non-stater for building containers with it.