BTL: by default use current Eigen headers, and disable the novec version
BTL: by default use current Eigen headers, and disable the novec version

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