getting rid of accidental checkin
Revert "turn on new double-width convolution"

This reverts commit e897a18d468080423d8ed21f2b65289ac87f92bc.
Revert "getting rid of accidental checkin"

This reverts commit 559d8c9ff2c9c994e7b31b5692a1b7db3ce103a2.
still getting rid of accidental commit
Revert "double-width convolutions using just pointers, no mallocs"

This reverts commit e16d7dd270aaf1e2248469ba8ea98d113a160268.