libcontainer: move Config in a separate package

We are going to import the namespaces package into libcontainer,
so libcontainer should not be imported into namespaces.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
libcontainer: move State in the configs package

We are going to import the namespaces package into libcontainer,
so libcontainer should not be imported into namespaces.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
nsinit: clean up

Signed-off-by: Andrey Vagin <avagin@openvz.org>
linux_container: fork an init process in a new set of namespaces
libcontainer: optimize updateStateFile()

Signed-off-by: Andrey Vagin <avagin@openvz.org>
process: use io.Reader instead of io.WriteCloser for standard fds

Could someone explain why we should close this fds? Usually users
cares about closing them or not.
For example exec.Cmd declares them as io.Reader.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
libcontinaer: use new API in integration tests

Signed-off-by: Andrey Vagin <avagin@openvz.org>
namespaces: combine Process.Env and Container.Env

Signed-off-by: Andrey Vagin <avagin@openvz.org>