Merge branch 'jn/parse-options-extra'

* jn/parse-options-extra: update-index: migrate to parse-options API setup: save prefix (original cwd relative to toplevel) in startup_info parse-options: make resuming easier after PARSE_OPT_STOP_AT_NON_OPTION parse-options: allow git commands to invent new option types parse-options: never suppress arghelp if LITERAL_ARGHELP is set parse-options: do not infer PARSE_OPT_NOARG from option type parse-options: sanity check PARSE_OPT_NOARG flag parse-options: move NODASH sanity checks to parse_options_check parse-options: clearer reporting of API misuse parse-options: Don't call parse_options_check() so much