* Apply http://opensimulator.org/mantis/view.php?id=2750 with a small tweak.

* Initializes ODE only when a scene is grabbed rather than on plugin load.  This means we don't initialize ode if that physics engine is not used, and it allows other ode use 
plugins to be used instead.

OpenSim/Region/Physics/OdePlugin/OdePlugin.cs

@@ -59,7 +59,6 @@ namespace OpenSim.Region.Physics.OdePlugin
 
         public bool Init()
         {
-            d.InitODE();
             return true;
         }
 
@@ -67,6 +66,10 @@ namespace OpenSim.Region.Physics.OdePlugin
         {
             if (_mScene == null)
             {
+                // Initializing ODE only when a scene is created allows alternative ODE plugins to co-habit (according to
+                // http://opensimulator.org/mantis/view.php?id=2750).
+                d.InitODE();
+                
                 _mScene = new OdeScene(ode);
             }
             return (_mScene);