Revert "Ensure the major version's incremental directory gets created"

This reverts commit c12d212012b52150500101c844aa7dedce4e9e0d.
Revert "oops - pass 3rd arg to publish-incrementals script"

This reverts commit 4b769d912ac10712015834ae985ebfa94504981c.
Revert "Put 3.x incrementals in a 3.x subdirectory"

This reverts commit 93db1c66a812c66c5c972b65b12637df6b828d60.