server: store and use image's stop signal to stop containers

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/opencontainers/image-spec/specs-go/v1/index.go

@@ -0,0 +1,29 @@
+// Copyright 2016 The Linux Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v1
+
+import "github.com/opencontainers/image-spec/specs-go"
+
+// Index references manifests for various platforms.
+// This structure provides `application/vnd.oci.image.index.v1+json` mediatype when marshalled to JSON.
+type Index struct {
+	specs.Versioned
+
+	// Manifests references platform specific manifests.
+	Manifests []Descriptor `json:"manifests"`
+
+	// Annotations contains arbitrary metadata for the image index.
+	Annotations map[string]string `json:"annotations,omitempty"`
+}