There's no reason that git-fast-import benefits from being a separate
binary. And as it links against libgit.a, it has a non-trivial disk
footprint. Let's make it a builtin, which reduces the size of a stripped
installation from 22MB to 21MB.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>