apply: mark include/exclude options as NONEG

apply: mark include/exclude options as NONEG

The options callback for "git apply --no-include" is not ready to handle
the "unset" parameter, and as a result will segfault when it adds a NULL
argument to the include list (likewise for "--no-exclude").

In theory this might be used to clear the list, but since both
"--include" and "--exclude" add to the same list, it's not immediately
obvious what the semantics should be. Let's punt on that for now and
just disallow the broken options.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>