Moby imports Swarmkit; Swarmkit no longer imports Moby. In order to
accomplish this feat, Swarmkit has introduced a new plugin.Getter
interface so it could stop importing our pkg/plugingetter package. This
new interface is not entirely compatible with our
plugingetter.PluginGetter interface, necessitating a thin adapter.

Swarmkit had to jettison the CNM network allocator to stop having to
import libnetwork as the cnmallocator package is deeply tied to
libnetwork. Move the CNM network allocator into libnetwork, where it
belongs. The package had a short an uninteresting Git history in the
Swarmkit repository so no effort was made to retain history.

Signed-off-by: Cory Snider <csnider@mirantis.com>
(cherry-picked from commit 7b0ab10)

d/cluster/convert: expose Addr() on plugins

The swarmPlugin type does not implement the Swarm plugin.AddrPlugin
interface because it embeds an interface value which does not include
that method in its method set. (You can type-assert an interface value
to another interface which the concrete type implements, but a struct
embedding an interface value is not itself an interface value.) Wrap the
plugin with a different adapter type which exposes the Addr() method if
the concrete plugin implements it.

Signed-off-by: Cory Snider <csnider@mirantis.com>
(cherry picked from commit 8b6d6b9)

libnetwork/cnmallocator: fix non-constant format string in call (govet)

    libnetwork/cnmallocator/drivers_ipam.go:43:31: printf: non-constant format string in call to (*github.com/docker/docker/vendor/github.com/sirupsen/logrus.Entry).Infof (govet)
            log.G(context.TODO()).Infof("Swarm initialized global default address pool to: " + str.String())
                                        ^

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 7b60a70)

Signed-off-by: Cory Snider <csnider@mirantis.com>