varregion: serious rework of TerrainChannel:

-- addition of varaible region size in X and Y
    -- internal storage of heightmap changed from double[] to short[]
    -- helper routines for handling internal structure while keeping existing API
    -- to and from XML that adds region size information (for downward compatibility,
        output in the legacy XML format if X and Y are 256)
Updated and commented Constants.RegionSize but didn't change the name for compatibility.

OpenSim/Region/ClientStack/Linden/UDP/LLClientView.cs

@@ -1240,9 +1240,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             try
             {
                 int[] patches = new int[] { py * 16 + px };
-                float[] heightmap = (map.Length == 65536) ?
-                    map :
-                    LLHeightFieldMoronize(map);
+                float[] heightmap = (map.Length == 65536) ? map : LLHeightFieldMoronize(map);
 
                 LayerDataPacket layerpack = TerrainCompressor.CreateLandPacket(heightmap, patches);