[PATCH/RFCv2 0/6] update-index: migrate to parse-options API

Here's a reroll. Changes explained in the comments following each patch.

Thanks to Stephen for a great deal of helpful advice. The result turns out to be less surgery than I thought from the version in pu, mostly because I am trying to be conservative (meaning further simplifications are welcome as patches on top, natch).

Based against ca20906, as before.

Jonathan Nieder (4):
  parse-options: sanity check PARSE_OPT_NOARG flag
  parse-options: allow git commands to invent new option types
  parse-options: make resuming easier after
    PARSE_OPT_STOP_AT_NON_OPTION
  update-index: migrate to parse-options API

Nguyễn Thái Ngọc Duy (1):
  setup: save prefix (original cwd relative to toplevel) in
    startup_info

Stephen Boyd (1):
  parse-options: eliminate implicit PARSE_OPT_NOARG for built-in option
    types

 builtin/update-index.c |  391 ++++++++++++++++++++++++++++++------------------
 cache.h                |    1 +
 parse-options.c        |   47 ++++---
 parse-options.h        |    9 +-
 setup.c                |    4 +-
 5 files changed, 283 insertions(+), 169 deletions(-)