Changed Rollback to Virtual

All methods in `TopicRepositoryBase` should allow optional overriding in concrete implementations, if necessary—even though `Rollback` may not generally need it, due to its nature.

Fixed formatting for `args` while I was at it (since it's not near other variable declarations, the alignment isn't necessary or consistent).

Author: JeremyCaney

Ignia.Topics/Repositories/TopicRepositoryBase.cs

@@ -152,7 +152,7 @@ public static Topic Load(XmlNode node, ImportStrategy importStrategy = ImportStr
     ///   exception="T:System.ArgumentNullException">
     ///   !VersionHistory.Contains(version)
     /// </requires>
-    public void Rollback(Topic topic, DateTime version) {
+    public virtual void Rollback(Topic topic, DateTime version) {
 
       /*------------------------------------------------------------------------------------------------------------------------
       | Retrieve topic from database
@@ -238,7 +238,7 @@ public virtual int Save(Topic topic, bool isRecursive = false, bool isDraft = fa
       | Trigger event
       \-----------------------------------------------------------------------------------------------------------------------*/
       if (topic.OriginalKey != null && topic.OriginalKey != topic.Key) {
-        var       args    = new RenameEventArgs(topic);
+        var args = new RenameEventArgs(topic);
         RenameEvent?.Invoke(this, args);
       }