- Add Dispose method to IRegionDataStore

- Add necessary dummy Dispose-methods where they are missing
- Implement the SQLite Dispose-methods
(currently only used for unit tests, in the next commit)

OpenSim/Data/Null/NullDataStore.cs

@@ -43,6 +43,10 @@ namespace OpenSim.Data.Null
             return;
         }
 
+        public void Dispose()
+        {
+        }
+
         public void StoreRegionSettings(RegionSettings rs)
         {
         }