Reorganised the Group::removeChild and Geode::removeDrawable methods so

that removeChild(Node*), removeChild(uint) and equivilant Geode methods are
now inline methods, not designed to be overriden, and seperated out the
multiple remove method to be called removeChildren(uint, uint) which is
now the only virtual method.  There removeChildren is now the method to
override in subclasses.

This reorganisation requires some call code to be rename removeChild usage
to removeChildren.

include/osg/ProxyNode

@@ -35,7 +35,8 @@ class OSG_EXPORT ProxyNode : public Group
        
         virtual bool addChild(Node *child);
         virtual bool addChild(Node *child, const std::string& filename);
-        virtual bool removeChild(Node *child);
+        
+        virtual bool removeChildren(unsigned int pos,unsigned int numChildrenToRemove);
 
         /** Set the database path to prepend to children's filenames.*/
         void setDatabasePath(const std::string& path);