Add per-instance date to DNE to avoid serializing stuff 10 times a second.

Clode cleanup and removal of commented stuff in ScriptManager.

OpenSim/Region/ScriptEngine/Common/IScript.cs

@@ -32,10 +32,7 @@ namespace OpenSim.Region.ScriptEngine.Common
 {
     public interface IScript
     {
-        string State { get; set; }
-        int StartParam { get; set; }
         ExecutorBase Exec { get; }
-        string Source { get; set; }
         void InitApi(string api, IScriptApi LSL_Functions);
     }
 }