Added support for shallow and deep copy of nodes, drawables and state, via a

copy constructor which takes an optional Cloner object, and the old
osg::Object::clone() has changed so that it now requires a Cloner as paramter.
This is passed on to the copy constructor to help control the shallow vs
deep copying.  The old functionality of clone() which was clone of type has
been renamed to cloneType().

Updated all of the OSG to work with these new conventions, implemention all
the required copy constructors etc.  A couple of areas will do shallow
copies by design, a couple of other still need to be updated to do either
shallow or deep.

Neither of the shallow or deep copy operations have been tested yet, only
the old functionality of the OSG has been checked so far, such running the
viewer on various demo datasets.

Also fixed a problem in osg::Optimize::RemoveRendundentNodesVisitor which
was not checking that Group didn't have have any attached StateSet's, Callbacks
or UserData.  These checks have now been added, which fixes a bug which was
revealled by the new osgscribe demo, this related to removal of group acting
as state decorator.

method

include/osg/Object

@@ -6,6 +6,7 @@
 #define OSG_OBJECT 1
 
 #include <osg/Referenced>
+#include <osg/ShallowCopy>
 
 namespace osg {
 
@@ -13,10 +14,11 @@ namespace osg {
   * Use when subclassing from Object to make it more convinient to define 
   * the standard pure virtual clone, isSameKindAs and className methods 
   * which are required for all Object subclasses.*/
-#define META_Object(name) \
-        virtual osg::Object* clone() const { return new name (); } \
-        virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const name *>(obj)!=NULL; } \
-        virtual const char* className() const { return #name; }
+#define META_Object(T) \
+        virtual osg::Object* cloneType() const { return new T (); } \
+        virtual osg::Object* clone(const osg::Cloner& cloner) const { return new T (*this,cloner); } \
+        virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const T *>(obj)!=NULL; } \
+        virtual const char* className() const { return #T; }
 
 
 /** Base class/standard interface for objects which require IO support, 
@@ -26,15 +28,25 @@ namespace osg {
 class SG_EXPORT Object : public Referenced
 {
     public:
+
+
         /** Construct an object. Note Object is a pure virtual base class
             and therefore cannot be constructed on its own, only derived
             classes which override the clone and className methods are
             concrete classes and can be constructed.*/
         Object() {}
 
-        /** return a shallow copy of a node, with Object* return type.
+        /** Copy constructor, optional Cloner object can be used to control
+          * shallow vs deep copying of dynamic data.*/
+        Object(const Object&,const Cloner& cloner=ShallowCopy());
+
+        /** Clone the type of an object, with Object* return type.
             Must be defined by derived classes.*/
-        virtual Object* clone() const = 0;
+        virtual Object* cloneType() const = 0;
+
+        /** Clone the an object, with Object* return type.
+            Must be defined by derived classes.*/
+        virtual Object* clone(const Cloner&) const = 0;
 
         virtual bool isSameKindAs(const Object*) const { return true; }
 
@@ -55,8 +67,7 @@ class SG_EXPORT Object : public Referenced
 
     private:
 
-        /** disallow any form of deep copy.*/
-        Object(Object&): Referenced() {}
+        /** disallow any copy operator.*/
         Object& operator = (const Object&) { return *this; }
 };