Prevent Move() on new Topic

Currently, `Move()` is called during `Save()` if the `ParentId` has changed prior to the last `Save()` or `Load()`. This is a reasonable assumption for existing topics. For new topics, however, it leads to a `Topic` being moved in the database even though that `Topic` doesn't yet exist. To mitigate this, put in an exception to check the status of the topic.

Author: JeremyCaney

Ignia.Topics/Repositories/TopicRepositoryBase.cs

@@ -178,7 +178,7 @@ public virtual int Save(Topic topic, bool isRecursive = false, bool isDraft = fa
       /*----------------------------------------------------------------------------------------------------------------------
       | Perform reordering and/or move
       \---------------------------------------------------------------------------------------------------------------------*/
-      if (topic.Parent != null && topic.Attributes.IsDirty("ParentId")) {
+      if (topic.Parent != null && topic.Attributes.IsDirty("ParentId") && topic.Id >= 0) {
         var topicIndex = topic.Parent.Children.IndexOf(topic);
         if (topicIndex > 0) {
           Move(topic, topic.Parent, topic.Parent.Children[topicIndex - 1]);