API definitions for the TE Topology Core App.

This APP creates and manages a hierarchy of TE topologies received from SBI TE provider and from user configurations from NBI.
The API contains internal data structures for TE attributes that are aligned with the TE attributes definition in standard IETF YANG TE topology model (https://tools.ietf.org/html/draft-ietf-teas-yang-te-topo-05).

This commit includes the following interface definitions:
- TE topology provider service, which is called by the TE topology provider from SB to pass TE topologies to the TE topology core APP
- TE topology service, which provides service APIs for an external APP to get/set TE topologies and their attributes.
- Network, Node, Link definitions for TE networks and their default class implementation

Change-Id: Iafcf6911b8d9e494397e3a255cae282bbca74d5c
diff --git a/apps/tetopology/src/main/java/org/onosproject/tetopology/management/api/TeTopologyProviderService.java b/apps/tetopology/src/main/java/org/onosproject/tetopology/management/api/TeTopologyProviderService.java
new file mode 100644
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--- /dev/null
+++ b/apps/tetopology/src/main/java/org/onosproject/tetopology/management/api/TeTopologyProviderService.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.tetopology.management.api;
+
+import org.onosproject.net.provider.ProviderService;
+import org.onosproject.tetopology.management.api.link.NetworkLink;
+import org.onosproject.tetopology.management.api.link.NetworkLinkKey;
+import org.onosproject.tetopology.management.api.node.NetworkNode;
+import org.onosproject.tetopology.management.api.node.NetworkNodeKey;
+import org.onosproject.tetopology.management.api.node.TerminationPoint;
+import org.onosproject.tetopology.management.api.node.TerminationPointKey;
+
+/**
+ * APIs for Provider to notify Manager about the network topology updates.
+ */
+public interface TeTopologyProviderService
+           extends ProviderService<TeTopologyProvider> {
+
+    /**
+     * Signals that a Network has been created/updated.
+     *
+     * @param network value of the network to be updated
+     */
+    void networkUpdated(Network network);
+
+    /**
+     * Signals that a Network has been removed.
+     *
+     * @param networkId network id in URI format
+     */
+    void networkRemoved(KeyId networkId);
+
+    /**
+     * Signals that a Link has been created/updated.
+     *
+     * @param linkKey link id
+     * @param link link object to be updated
+    */
+    void linkUpdated(NetworkLinkKey linkKey, NetworkLink link);
+
+    /**
+     * Signals that a Network has been removed.
+     *
+     * @param linkKey link id
+     */
+    void linkRemoved(NetworkLinkKey linkKey);
+
+    /**
+     * Signals that a Node has been created/updated.
+     *
+     * @param nodeKey node id
+     * @param node node object to be updated
+     */
+    void nodeUpdated(NetworkNodeKey nodeKey, NetworkNode node);
+
+    /**
+     * Signals that a Node has been removed.
+     *
+     * @param nodeKey node id
+     */
+    void nodeRemoved(NetworkNodeKey nodeKey);
+
+    /**
+     * Signals that a TerminationPoint has been created/updated.
+     *
+     * @param terminationPointKey termination point id
+     * @param terminationPoint termination point object to be updated
+     */
+    void terminationPointUpdated(TerminationPointKey terminationPointKey,
+                                TerminationPoint terminationPoint);
+
+    /**
+     * Signals that a TerminationPoint has been removed.
+     *
+     * @param terminationPointKey termination point id
+     */
+    void terminationPointRemoved(TerminationPointKey terminationPointKey);
+
+}