[PATCH v2 00/11][Outreachy] Improve the 'fixup [-C | -c]' in interactive rebase

This patch series is build on the top of "cm/rebase-i" in the 'next' branch and improves it. It fixup the source code of 'fixup [-C | -c]' command in the sequencer, do some fixes in rebase -i, improves the 'fixup_-C' like commands in lib-rebase.sh, update the test-script 't3437' and fixes a typo in the documentation.

Changes from v1 :
* Splits the patch 'update test-script', to make it more easy to follow.
* Modification in few commit messages as suggested by Eric.

Charvi Mendiratta (11):
  sequencer: fixup the datatype of the 'flag' argument
  sequencer: rename a few functions
  rebase -i: clarify and fix 'fixup -c' rebase-todo help
  t/lib-rebase: change the implementation of commands with options
  t/t3437: fix indentation of the here-doc
  t/t3437: remove the dependency of 'expected-message' file from tests
  t/t3437: check author date of the fixed up commit
  t/t3437: simplify and document the test helpers
  t/t3437: cleanup the 'setup' test and use named commits in the tests
  t/t3437: fixup the test 'multiple fixup -c opens editor once'
  doc/rebase -i: fix typo in the documentation of 'fixup' command

 Documentation/git-rebase.txt    |   2 +-
 rebase-interactive.c            |   6 +-
 sequencer.c                     |  23 +++---
 t/lib-rebase.sh                 |   8 +-
 t/t3437-rebase-fixup-options.sh | 140 +++++++++++++++++---------------
 5 files changed, 94 insertions(+), 85 deletions(-)

-- 2.29.0.rc1