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/AlarmProviderRegistry.java b/core/api/src/main/java/org/onosproject/alarm/AlarmProviderRegistry.java
new file mode 100644
index 0000000..32e812d
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/alarm/AlarmProviderRegistry.java
@@ -0,0 +1,25 @@
+/*
+ * 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 org.onosproject.net.provider.ProviderRegistry;
+
+/**
+ * Abstraction of a alarm provider registry.
+ */
+public interface AlarmProviderRegistry extends ProviderRegistry<AlarmProvider, AlarmProviderService> {
+}