Nova Docker driver must remove network namespace

Change-Id: I6fa306d06fb16f8ceddb06e22566974237082759
Closes-Bug: 1261007
nova docker driver cannot find cgroup in /proc/mounts on RHEL

Change-Id: Ie24028f822d91d65d4f90a7941e7b11874a3b425
Closes-Bug: #1243101
Docker Driver doesn't respect CPU limit

The docker driver doesn't respect the CPU settings of the configured
flavor.

Docker/LXC supports only relative cpu allocation. The relative
cpu allocation doesn't prevent that a container can use all CPUs but it
can at least ensure that a container with more CPUs gets more CPU
cycles.

DocImpact - Docker containers are now given CPU shares according to
the vcpu setting of the flavor used when creating the container.
Previously, the vcpu field was ignored and all containers got equal
CPU shares, regardless of the vcpu setting.

Change-Id: I7184eddfd8bbd2cbaa07a48ebb40bc9aa3fbd4a9
Closes-Bug: #1256264
Nova Docker: Metadata service doesn't work

The metadata services rejects the request because the remote IP address
belongs to the docker network. The remote IP address is correct by using
the nova network as default route.

Change-Id: I410a9bfea560f669515b31db7f007515b4d5c4e7
Closes-Bug: #1259267
Closes-Bug: #1261021
Merge commit 'refs/changes/83/62183/4' of https://review.openstack.org/openstack/nova
Merge commit 'refs/changes/24/59824/14' of https://review.openstack.org/openstack/nova
Merge commit 'refs/changes/82/62182/3' of https://review.openstack.org/openstack/nova
Merge commit 'refs/changes/20/62220/2' of https://review.openstack.org/openstack/nova