This moves the Attach method from the container to the daemon. This
method mostly supports the http attach logic and does not have anything
to do with the running of a container.
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Upstream-commit: 41cfaa738c2d8583ecca50948c9df5eda3dfd7f1
Component: engine