fix issue #125 - *norm() return RealScalar and not Scalar
fix issue #125 - *norm() return RealScalar and not Scalar

madlib/eigen_backup,madlib/eigen_backup,rotorliu/eigen,madlib/eigen_backup,madlib/eigen_backup,rotorliu/eigen,mjbshaw/Eigen,mjbshaw/Eigen,rotorliu/eigen,rotorliu/eigen,mjbshaw/Eigen,mjbshaw/Eigen