Detangling incubator: virtual nets, tunnels, resource labels, oh my

- virtual networking moved to /apps/virtual; with CLI & REST API
- tunnels and labels moved to /apps/tunnel; with CLI & REST API; UI disabled for now
- protobuf/models moved to /core/protobuf/models
- defunct grpc/rpc registry stuff left under /graveyard
- compile dependencies on /incubator moved to respective modules for compilation
- run-time dependencies will need to be re-tested for dependent apps

- /graveyard will be removed in not-too-distant future

Change-Id: I0a0b995c635487edcf95a352f50dd162186b0b39
diff --git a/core/api/src/main/java/org/onosproject/alarm/AlarmId.java b/core/api/src/main/java/org/onosproject/alarm/AlarmId.java
new file mode 100644
index 0000000..39cd5b6
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/alarm/AlarmId.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2018-present Open Networking 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 org.onosproject.alarm;
+
+import com.google.common.annotations.Beta;
+import org.onlab.util.Identifier;
+import org.onosproject.net.DeviceId;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Alarm identifier suitable as an external key.
+ * <p>
+ * This class is immutable.</p>
+ */
+@Beta
+public final class AlarmId extends Identifier<String> {
+
+    /**
+     * Instantiates a new Alarm id.
+     *
+     * @param id               the device id
+     * @param uniqueIdentifier the unique identifier of the Alarm on that device
+     */
+    private AlarmId(DeviceId id, String uniqueIdentifier) {
+        super(id.toString() + ":" + uniqueIdentifier);
+        checkNotNull(id, "device id must not be null");
+        checkNotNull(uniqueIdentifier, "unique identifier must not be null");
+        checkArgument(!uniqueIdentifier.isEmpty(), "unique identifier must not be empty");
+    }
+
+    /**
+     * Instantiates a new Alarm id, primarily meant for lookup.
+     *
+     * @param globallyUniqueIdentifier the globally unique identifier of the Alarm,
+     *                                 device Id + local unique identifier on the device
+     */
+    private AlarmId(String globallyUniqueIdentifier) {
+        super(globallyUniqueIdentifier);
+        checkArgument(!globallyUniqueIdentifier.isEmpty(), "unique identifier must not be empty");
+    }
+
+    /**
+     * Creates an alarm identifier from the specified device id and
+     * unique identifier provided representation.
+     *
+     * @param id               device id
+     * @param uniqueIdentifier per device unique identifier of the alarm
+     * @return alarm identifier
+     */
+    public static AlarmId alarmId(DeviceId id, String uniqueIdentifier) {
+        return new AlarmId(id, uniqueIdentifier);
+    }
+
+    /**
+     * Creates an alarm identifier from the specified globally unique identifier.
+     *
+     * @param globallyUniqueIdentifier the globally unique identifier of the Alarm,
+     *                                 device Id + local unique identifier on the device
+     * @return alarm identifier
+     */
+    public static AlarmId alarmId(String globallyUniqueIdentifier) {
+        return new AlarmId(globallyUniqueIdentifier);
+    }
+
+}