[PATCHv5 0/8] Add commit message options for rebase --autosquash

This patch series adds new command line options to git-commit to make it easy to specify messages for commits correctly formatted for use wit 'rebase -i --autosquash'.

The first three patches introduce minor refactorings that set the stage for subsequent patches.

The fourth patch teaches format_commit_message to reencode the content if the caller's commit object uses an encoding different from the commit encoding.

The remaining patches add the --fixup and --squash commands to git-commit including tests of commit, interactions with rebase and i18n encodings.

One issue which limits the testing (but not the implementation, I think) is that when 'rebase --autosquash' is comparing commit subject lines it does not first make sure that the commits use a common encoding. That's follow-on work.

Pat Notz (8):
  commit.c: prefer get_header() to manual searching
  commit.c: new function for looking up a comit by name
  pretty.c: helper methods for getting output encodings
  pretty.c: teach format_commit_message() to reencode the output
  commit: --fixup option for use with rebase --autosquash
  add tests of commit --fixup
  commit: --squash option for use with rebase --autosquash
  add tests of commit --squash

 Documentation/git-commit.txt |   21 +++++++++--
 archive.c                    |    2 +-
 builtin/commit.c             |   76 +++++++++++++++++++++++++++------------
 builtin/fmt-merge-msg.c      |    2 +-
 cache.h                      |    3 ++
 commit.c                     |   13 +++++++
 commit.h                     |    5 ++-
 environment.c                |   11 ++++++
 log-tree.c                   |    2 +-
 notes-cache.c                |    2 +-
 pretty.c                     |   47 +++++++++++++++++++-----
 submodule.c                  |    4 +-
 t/t3415-rebase-autosquash.sh |   29 ++++++++++++++-
 t/t3900-i18n-commit.sh       |   28 +++++++++++++++
 t/t7500-commit.sh            |   80 ++++++++++++++++++++++++++++++++++++++++++
 t/t7500/edit-content         |    4 ++
 16 files changed, 283 insertions(+), 46 deletions(-)
 create mode 100755 t/t7500/edit-content