Refactored tunnel and interface config behavior

- Added tunnel interface configuratoin to interfaceConfig and
  deprecated tunnelConfig
- OVSDB client service provides interface create/remove APIs instead
  of tunnel interface create/remove, and this APIs can be used to
  create/remove various types of interfaces like tunnel, patch, tap and so on
- Use tunnel description when create tunnel interface so that we can extend
  more config options later
- Some cleaup OVSDB client

Change-Id: I4653595504a27b18384a92ebe4b31ce9d99237cd
diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/TunnelKey.java b/core/api/src/main/java/org/onosproject/net/behaviour/TunnelKey.java
new file mode 100644
index 0000000..527b44a
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/TunnelKey.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016-present 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.net.behaviour;
+
+import java.util.Objects;
+
+/**
+ * Represent for a tunnel key. The tunnel accepts packets with the tunnel key.
+ * A positive 24-bit (for Geneve, VXLAN, and LISP), 32-bit (for GRE) or 64-bit (for
+ * GRE64) number value is used for example. Open vSwitch allows "flow" as the key
+ * to set this value with matching in the flow table.
+ */
+public final class TunnelKey<T> {
+
+    private final T value;
+
+    /**
+     * Default constructor.
+     *
+     * @param value value of the tunnel key
+     */
+    public TunnelKey(T value) {
+        this.value = value;
+    }
+
+    /**
+     * Returns the value.
+     *
+     * @return tunnel key value
+     */
+    public T value() {
+        return value;
+    }
+
+    /**
+     * Returns the value as a string.
+     *
+     * @return string value
+     */
+    public String strValue() {
+        return value.toString();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof TunnelKey) {
+            final TunnelKey that = (TunnelKey) obj;
+            return this.getClass() == that.getClass() &&
+                    Objects.equals(this.value, that.value);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return value.hashCode();
+    }
+}