Fixes Mantis #3260. Thank you kindly, MCortez for a patch that:

llSetHoverHeight() should not clamp the x/y position of an object the way MoveTo does, 
and it should recalculate the absolute height to hover at as an object moves to reflect 
the current ground/water height under it.
Correctly implementing required adjusting the Physics interfaces and implementing at 
the physics plug-in level. The attached is a patch that correctly implements 
llSetHoverHeight() including updates to the ODE physics plug-in.

1 files changed, 13 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/PhysXPlugin/PhysXPlugin.cs b/OpenSim/Region/Physics/PhysXPlugin/PhysXPlugin.cs
index 120eed9..7bbca9d 100644
--- a/OpenSim/Region/Physics/PhysXPlugin/PhysXPlugin.cs
+++ b/OpenSim/Region/Physics/PhysXPlugin/PhysXPlugin.cs
@@ -490,9 +490,16 @@ namespace OpenSim.Region.Physics.PhysXPlugin
         {
 
         }
+
         public override PhysicsVector PIDTarget { set { return; } }
         public override bool PIDActive { set { return; } }
         public override float PIDTau { set { return; } }
+
+        public override float PIDHoverHeight { set { return; } }
+        public override bool PIDHoverActive { set { return; } }
+        public override PIDHoverType PIDHoverType { set { return; } }
+        public override float PIDHoverTau { set { return; } }
+
         public override void SubscribeEvents(int ms)
         {
 
@@ -765,10 +772,16 @@ namespace OpenSim.Region.Physics.PhysXPlugin
         public override void CrossingFailure()
         {
         }
+
         public override PhysicsVector PIDTarget { set { return; } }
         public override bool PIDActive { set { return; } }
         public override float PIDTau { set { return; } }
 
+        public override float PIDHoverHeight { set { return; } }
+        public override bool PIDHoverActive { set { return; } }
+        public override PIDHoverType PIDHoverType { set { return; } }
+        public override float PIDHoverTau { set { return; } }
+
         public override void SubscribeEvents(int ms)
         {