[ONOS-5070] Adds mirroring functionality.

Changes:
- Adds mirroring behaviour;
- Adds mirroring description;
- Adds mirroring name;
- Implements for Ovsdb the mirroring;
- Adds OvsdbMirror entity;
- Adds constants related to Mirror table;
- Fix one issue related to Mirror table
- Extends OvsdbClientService introducing mirroring;
- Implements mirroring functionality in DefaulOvsdbClient;
- Support for different types of device id

Change-Id: Ie291f49b3c61b7998010f555ae11deb8c021063d
diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/MirroringName.java b/core/api/src/main/java/org/onosproject/net/behaviour/MirroringName.java
new file mode 100644
index 0000000..82b0eb7
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/MirroringName.java
@@ -0,0 +1,78 @@
+/*
+ * 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 com.google.common.base.MoreObjects;
+
+import java.util.Objects;
+
+/**
+ * Represents for a mirroring name.
+ */
+public final class MirroringName {
+
+    private final String name;
+
+    private MirroringName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * Creates a mirroring name using the supplied string.
+     *
+     * @param name mirroring name
+     * @return a port mirroring name
+     */
+    public static MirroringName mirroringName(String name) {
+        return new MirroringName(name);
+    }
+
+    /**
+     * Returns the mirroring name string.
+     *
+     * @return name string
+     */
+    public String name() {
+        return name;
+    }
+
+    @Override
+    public int hashCode() {
+        return name.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof MirroringName) {
+            final MirroringName that = (MirroringName) obj;
+            return this.getClass() == that.getClass() &&
+                    Objects.equals(this.name, that.name);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("name", name)
+                .toString();
+    }
+
+}