Feature/com/server multicast user added to user list

Concerns about where to put Interface implementations

src/baleine/client/network/messages/clientToServer/LoginUserToServerMessage.java

 package baleine.client.network.messages.clientToServer;
 
 import baleine.common.dataModel.UserLight;
+import baleine.common.interfaces.server.ComToDataImpl;
 import baleine.common.message.MessageMeta;
 
+import java.net.InetAddress;
+
 /**
  * Message containing a login request to send to the server.
  */
 public class LoginUserToServerMessage extends MessageMeta {
     private UserLight userToAdd;
+    private InetAddress userAddress;
 
     public LoginUserToServerMessage(UserLight userToAdd) {
         this.userToAdd = userToAdd;
     }
 
-    public LoginUserToServerMessage() {
+    public LoginUserToServerMessage(UserLight userToConnect, InetAddress address) {
+        this.userToAdd = userToConnect;
+        this.userAddress = address;
+    }
+
+    public InetAddress getUserAddress() {
+        return userAddress;
+    }
+
+    public void setUserAddress(InetAddress userAddress) {
+        this.userAddress = userAddress;
     }
 
     @Override
     public void processData() {
-        // TODO: Implement
+        /*
+         *  FIXME : The client only sends this type of message, never receives it.
+         *  Server receives this type of messages BUT has a copy of this type of messages Class.
+         *  Ground for confusion.
+         * */
+        ComToDataImpl.getInstance().addNewUser(this.userToAdd);
     }
 
     public UserLight getUserToAdd() {