Currently ls-remote uses a hand rolled parser for its command line
arguments. Use the parse-options api instead of the hand rolled parser
to simplify the code and make it easier to add new arguments. In
addition this improves the help message.
Helped-by: Jeff King <peff@peff.net> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>