Added support for decoration of the osgTerrain::DataSet generated databases

with a CoordinateSystemNode which reflect the coordinate system of the
database.

Added support for reading and writing CoordianteSystemNode into the .osg
and .ive formats.

include/osg/NodeVisitor

@@ -36,6 +36,7 @@ class Impostor;
 class ClearNode;
 class OccluderNode;
 class Sequence;
+class CoordinateSystemNode;
 
 /** Visitor for type safe operations on osg::Node's.
     Based on GOF's Visitor pattern. The NodeVisitor 
@@ -221,6 +222,8 @@ class SG_EXPORT NodeVisitor : public virtual Referenced
 
         virtual void apply(Projection& node)                { apply((Group&)node); }
 
+        virtual void apply(CoordinateSystemNode& node)      { apply((Group&)node); }
+
         virtual void apply(ClipNode& node)                  { apply((Group&)node); }
         virtual void apply(LightSource& node)               { apply((Group&)node); }