Move "pause" to daemon/pause.go

This is part of an effort to break apart the deprecated server/ package

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Move "unpause" to daemon/pause.go

This is part of an effort to break apart the deprecated server/ package

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)