Device tagging API support

This patch allows the user to specify a tag for a virtual network
interface and/or block device mapping when booting an instance.

Implements: blueprint bp/virt-device-role-tagging
Change-Id: I89247200f4cf1f644daf476727b4a6acb22b0cf6

doc/api_samples/servers/v2.32/server-create-req.json

@@ -0,0 +1,18 @@
+{
+    "server" : {
+        "name" : "device-tagging-server",
+        "flavorRef" : "http://openstack.example.com/flavors/1",
+        "networks" : [{
+            "uuid" : "ff608d40-75e9-48cb-b745-77bb55b5eaf2",
+            "tag": "nic1"
+        }],
+        "block_device_mapping_v2": [{
+            "uuid": "70a599e0-31e7-49b7-b260-868f441e862b",
+            "source_type": "image",
+            "destination_type": "volume",
+            "boot_index": 0,
+            "volume_size": "1",
+            "tag": "disk1"
+        }]
+    }
+}

doc/api_samples/servers/v2.32/server-create-resp.json

@@ -0,0 +1,22 @@
+{
+    "server": {
+        "adminPass": "rojsEujtu7GB",
+        "OS-DCF:diskConfig": "AUTO",
+        "id": "05ec6bde-40bf-47e8-ac07-89c12b2eee03",
+        "links": [
+            {
+                "href": "http://openstack.example.com/v2.1/6f70656e737461636b20342065766572/servers/05ec6bde-40bf-47e8-ac07-89c12b2eee03",
+                "rel": "self"
+            },
+            {
+                "href": "http://openstack.example.com/6f70656e737461636b20342065766572/servers/05ec6bde-40bf-47e8-ac07-89c12b2eee03",
+                "rel": "bookmark"
+            }
+        ],
+        "security_groups": [
+            {
+                "name": "default"
+            }
+        ]
+    }
+}