Update parent inventory folder version numbers when folders are moved/created/deleted to match version numbers cached by viewers.

This is done in the way that one would expect (e.g. moving a folder increments version number on both source and destination parent folders).
This should hopefully improve viewer reuse of its cached inventory information.
Currently MySQL only but will be implement for SQLite/MSSQL if there are no issues.

OpenSim/Data/IXInventoryData.cs

@@ -116,7 +116,22 @@ namespace OpenSim.Data
         /// <returns>true if the delete was successful, false if it was not</returns>
         bool DeleteItems(string[] fields, string[] vals);
 
+        /// <summary>
+        /// Move an item to a new folder.
+        /// </summary>
+        /// <returns>/returns>
+        /// <param name='id'>UUID of the item</param>
+        /// <param name='newParent'>UUID of the new folder.</param>
         bool MoveItem(string id, string newParent);
+
+        /// <summary>
+        /// Move a folder to a new folder.
+        /// </summary>
+        /// <returns>/returns>
+        /// <param name='id'>UUID of the item</param>
+        /// <param name='newParent'>UUID of the new folder.</param>
+        bool MoveFolder(string id, string newParent);
+
         XInventoryItem[] GetActiveGestures(UUID principalID);
         int GetAssetPermissions(UUID principalID, UUID assetID);
     }