add {generate,play} kube

Add the `podman generate kube` and `podman play kube` command.  The code
has largely been copied from Podman v1 but restructured to not leak the
K8s core API into the (remote) client.

Both commands are added in the same commit to allow for enabling the
tests at the same time.

Move some exports from `cmd/podman/common` to the appropriate places in
the backend to avoid circular dependencies.

Move definitions of label annotations to `libpod/define` and set the
security-opt labels in the frontend to make kube tests pass.

Implement rest endpoints, bindings and the tunnel interface.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

pkg/api/server/register_generate.go

@@ -0,0 +1,41 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/containers/libpod/pkg/api/handlers/libpod"
+	"github.com/gorilla/mux"
+)
+
+func (s *APIServer) registerGenerateHandlers(r *mux.Router) error {
+	// swagger:operation GET /libpod/generate/{name:.*}/kube libpod libpodGenerateKube
+	// ---
+	// tags:
+	//  - containers
+	//  - pods
+	// summary: Play a Kubernetes YAML file.
+	// description: Create and run pods based on a Kubernetes YAML file (pod or service kind).
+	// parameters:
+	//  - in: path
+	//    name: name:.*
+	//    type: string
+	//    required: true
+	//    description: Name or ID of the container or pod.
+	//  - in: query
+	//    name: service
+	//    type: boolean
+	//    default: false
+	//    description: Generate YAML for a Kubernetes service object.
+	// produces:
+	// - application/json
+	// responses:
+	//   200:
+	//     description: no error
+	//     schema:
+	//      type: string
+	//      format: binary
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/generate/{name:.*}/kube"), s.APIHandler(libpod.GenerateKube)).Methods(http.MethodGet)
+	return nil
+}