Added rotation of billboard normal into flattern transform Optimizer pass.
Added rotation of billboard normal into flattern transform Optimizer pass.


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