Move libkpod/image libkpod/layer to libpod/images and libpod/layers

Begin moving image and layer handling out of libkpod into libpod.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

libpod/layers/layer.go

@@ -0,0 +1,12 @@
+package layers
+
+import cstorage "github.com/containers/storage"
+
+// FullID gets the full id of a layer given a partial id or name
+func FullID(store cstorage.Store, id string) (string, error) {
+	layer, err := store.Layer(id)
+	if err != nil {
+		return "", err
+	}
+	return layer.ID, nil
+}