pull: pass --signoff/--no-signoff to "git merge"
merge can take --signoff, but without pull passing --signoff down, it
is inconvenient to use; allow 'pull' to take the option and pass it
through.
The order of options in merge-options.txt is mostly alphabetical by
long option since
7c85d274 (Documentation/merge-options.txt: order
options in alphabetical groups, 2009-10-22). The long-option bit
didn't make it into the commit message, but it's under the fold in
[1]. I've put --signoff between --log and --stat to preserve the
alphabetical order.
[1]: https://public-inbox.org/git/87iqe7zspn.fsf@jondo.cante.net/
Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Junio C Hamano <gitster@pobox.com>