[PATCH 0/5] grep parseopt conversion

This series converts git-grep to parseopt.  The first three patches
extend the parser to accept inverse bit options, numerical options
and options without dashes:

   [PATCH 1/5] parseopt: add OPT_NEGBIT
   [PATCH 2/5] parseopt: add OPT_NUMBER_CALLBACK
   [PATCH 3/5] parseopt: add PARSE_OPT_NODASH

The fourth patch is a cleanup:

   [PATCH 4/5] grep: remove global variable builtin_grep

The last patch uses the added infrastructure in git-grep:

   [PATCH 5/5] grep: use parseopt

 Documentation/technical/api-parse-options.txt |   12 +
 builtin-grep.c                                |  416 +++++++++++--------------
 grep.h                                        |   28 +-
 parse-options.c                               |   63 ++++-
 parse-options.h                               |   14 +-
 t/t0040-parse-options.sh                      |   56 ++++-
 test-parse-options.c                          |   11 +
 7 files changed, 348 insertions(+), 252 deletions(-)