Restructured api to multiple packages

Change-Id: I8a3bb2297ef55fa7749bb312b01a4929d1b360f6
diff --git a/src/main/java/org/opencord/cordvtn/impl/InstanceManager.java b/src/main/java/org/opencord/cordvtn/impl/InstanceManager.java
index 4671c4d..fee0931 100644
--- a/src/main/java/org/opencord/cordvtn/impl/InstanceManager.java
+++ b/src/main/java/org/opencord/cordvtn/impl/InstanceManager.java
@@ -30,8 +30,8 @@
 import org.onosproject.cluster.NodeId;
 import org.opencord.cordconfig.CordConfigService;
 import org.opencord.cordconfig.access.AccessAgentData;
-import org.opencord.cordvtn.api.CordVtnService;
-import org.opencord.cordvtn.api.Instance;
+import org.opencord.cordvtn.api.core.CordVtnService;
+import org.opencord.cordvtn.api.instance.Instance;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
 import org.onosproject.dhcp.DhcpService;
@@ -51,12 +51,12 @@
 import org.onosproject.net.host.HostService;
 import org.onosproject.net.provider.AbstractProvider;
 import org.onosproject.net.provider.ProviderId;
-import org.opencord.cordvtn.api.InstanceService;
-import org.opencord.cordvtn.api.PortId;
-import org.opencord.cordvtn.api.VtnNetwork;
-import org.opencord.cordvtn.api.VtnNetworkEvent;
-import org.opencord.cordvtn.api.VtnNetworkListener;
-import org.opencord.cordvtn.api.VtnPort;
+import org.opencord.cordvtn.api.instance.InstanceService;
+import org.opencord.cordvtn.api.net.PortId;
+import org.opencord.cordvtn.api.net.VtnNetwork;
+import org.opencord.cordvtn.api.net.VtnNetworkEvent;
+import org.opencord.cordvtn.api.net.VtnNetworkListener;
+import org.opencord.cordvtn.api.net.VtnPort;
 import org.slf4j.Logger;
 
 import java.util.Date;
@@ -69,9 +69,9 @@
 import static org.onosproject.dhcp.IpAssignment.AssignmentStatus.Option_RangeNotEnforced;
 import static org.onosproject.net.AnnotationKeys.PORT_NAME;
 import static org.opencord.cordvtn.api.Constants.*;
-import static org.opencord.cordvtn.api.ServiceNetwork.ServiceNetworkType.ACCESS_AGENT;
-import static org.opencord.cordvtn.api.ServiceNetwork.ServiceNetworkType.MANAGEMENT_HOST;
-import static org.opencord.cordvtn.api.ServiceNetwork.ServiceNetworkType.MANAGEMENT_LOCAL;
+import static org.opencord.cordvtn.api.net.ServiceNetwork.ServiceNetworkType.ACCESS_AGENT;
+import static org.opencord.cordvtn.api.net.ServiceNetwork.ServiceNetworkType.MANAGEMENT_HOST;
+import static org.opencord.cordvtn.api.net.ServiceNetwork.ServiceNetworkType.MANAGEMENT_LOCAL;
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**