urdf parser should not check if mesh files exist
urdf parser should not check if mesh files exist

robotology-dependencies/urdfdom,shadow-robot/urdfdom,keulYSMB/urdfdom,shadow-robot/urdfdom,robotology-dependencies/urdfdom,robotology-dependencies/urdfdom,robotology-dependencies/urdfdom,keulYSMB/urdfdom,keulYSMB/urdfdom,shadow-robot/urdfdom,keulYSMB/urdfdom,shadow-robot/urdfdom