Added implicit cast to T* to ref_ptr<>.
Added implicit cast to T* to ref_ptr<>.


artoolkit/osg,stmh/osg,omega-hub/osg,artoolkit/osg,koshman86/osg,ghub/osg,koshman86/osg,koshman86/osg,XiaoCC/osg,ntoand/osg,koshman86/osg,artoolkit/osg,ghub/osg,omega-hub/osg,stmh/osg,omega-hub/osg,ntoand/osg,ntoand/osg,XiaoCC/osg,XiaoCC/osg,stmh/osg,ntoand/osg,stmh/osg,ghub/osg,stmh/osg,artoolkit/osg,XiaoCC/osg,omega-hub/osg,ghub/osg,XiaoCC/osg