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/driver/driver.go

@@ -0,0 +1,27 @@
+package driver
+
+import cstorage "github.com/containers/storage"
+
+// Data handles the data for a storage driver
+type Data struct {
+	Name string
+	Data map[string]string
+}
+
+// GetDriverName returns the name of the driver for the given store
+func GetDriverName(store cstorage.Store) (string, error) {
+	driver, err := store.GraphDriver()
+	if err != nil {
+		return "", err
+	}
+	return driver.String(), nil
+}
+
+// GetDriverMetadata returns the metadata regarding the driver for the layer in the given store
+func GetDriverMetadata(store cstorage.Store, layerID string) (map[string]string, error) {
+	driver, err := store.GraphDriver()
+	if err != nil {
+		return nil, err
+	}
+	return driver.Metadata(layerID)
+}