CORD-151 Implement initial compute node setup

Followings are changed
- Changed nodeStore from eventually consistent map to consistent map
- Removed ovsdb connection management(ovsdb controller has connection status)
- Not only one leader but all onos instances make ovsdb session

Following jobs are done
- Reads compute node and ovsdb access info from network config
- Initiates ovsdb connection to the nodes
- Creates integration bridge on each ovsdbs
- Creates vxlan tunnel port on each integration bridges

Change-Id: I8df4061fcb1eae9b0abd545b7a3f540be50607a9
diff --git a/pom.xml b/pom.xml
index a019bec..b8e913d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -49,6 +49,11 @@
             <artifactId>onos-core-serializers</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-ovsdb-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
     </dependencies>
 
 </project>