- 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/MSSQL/MSSQLRegionData.cs

@@ -156,6 +156,11 @@ namespace OpenSim.Data.MSSQL
 
             //After this we have a empty fully configured DataSet.
         }
+        
+        /// <summary>
+        /// Dispose the database
+        /// </summary>
+        public void Dispose() {}
 
         /// <summary>
         /// Loads the objects present in the region.