The 'add' subcommand is useless as it is mostly identical
to the 'put' subcommand, so let's remove it.
Helped-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>