Script State Fix: Part 2

Change the reader to wrap old-style definitions in new style wrappers.
Change importer to not check irrelevant data that can't be reconstructed
This removes the last bit of knowledge of XEngine's .state files from core.

OpenSim/Region/Framework/Interfaces/IScriptModule.cs

@@ -35,7 +35,7 @@ namespace OpenSim.Region.Framework.Interfaces
         string ScriptEngineName { get; }
 
         string GetXMLState(UUID itemID);
-        void SetXMLState(UUID itemID, string xml);
+        bool SetXMLState(UUID itemID, string xml);
 
         bool PostScriptEvent(UUID itemID, string name, Object[] args);
         bool PostObjectEvent(UUID itemID, string name, Object[] args);