[RFC PATCH 0/5] Remove git-filter-branch from git.git; host it elsewhere

Following up on the suggestion to make git.git smaller and shed non-core tools, here's an RFC series to do so with git-filter-branch. This series first removes dependencies on git-filter-branch (of which there were very few), and then deletes git-filter-branch itself in the final commit.

I'm more than happy to consider alternate places for the filter-branch
history (I had considered just merging it in with git-filter-repo), but
for now I just made it available here:
        https://github.com/newren/git-filter-branch

The rewrite above contains the history of the files deleted in Patch 5, plus a one-time copy of relevant build files (Makefiles, test-lib.sh, etc. -- I didn't want the whole history of these), and then touchups to streamline the build files and make them all work in this standalone repo.

Some highlevel notes on the patches:

  * Patches 1&2: are good cleanups & performance wins regardless of
    whether the rest of the series is taken
    
  * Patch 3: an attempt to improve i18n situation for external scripts,
    but discovered to not be necessary/useful for git-filter-branch
    specifically

  * Patch 4:
    * If we are good with deleting git-filter-branch now and just noting
      it in the release notes, then patch 4 could be simplified; there's
      no need to update git-filter-branch.txt in that case.
    * If, however, we want to do some external messaging for an
      additional release cycle or two before moving git-filter-branch
      out of git.git, this patch will help us until then to at least
      avoid recommending a tool which will likely mangle user's data in
      unexpected ways.  But it'd be really helpful if folks could review
      and opine on the BFG stuff if so.

  * Patch 5: actually deletes git-filter-branch, its tests, and
    documentation.

Elijah Newren (5):
  t6006: simplify and optimize empty message test
  t3427: accelerate this test by using fast-export and fast-import
  git-sh-i18n: work with external scripts
  Recommend git-filter-repo instead of git-filter-branch in
    documentation
  Remove git-filter-branch, it is now external to git.git

 .gitignore                          |   1 -
 Documentation/git-fast-export.txt   |   6 +-
 Documentation/git-filter-branch.txt | 481 --------------------
 Documentation/git-gc.txt            |  17 +-
 Documentation/git-rebase.txt        |   2 +-
 Documentation/git-replace.txt       |  10 +-
 Documentation/git-svn.txt           |   4 +-
 Documentation/githooks.txt          |   7 +-
 Makefile                            |   1 -
 command-list.txt                    |   1 -
 contrib/svn-fe/svn-fe.txt           |   4 +-
 git-filter-branch.sh                | 662 ----------------------------
 git-sh-i18n.sh                      |   7 +-
 t/perf/p7000-filter-branch.sh       |  24 -
 t/t3427-rebase-subtree.sh           |  32 +-
 t/t6006-rev-list-format.sh          |   5 +-
 t/t7003-filter-branch.sh            | 505 ---------------------
 t/t7009-filter-branch-null-sha1.sh  |  55 ---
 t/t9902-completion.sh               |  12 +-
 19 files changed, 63 insertions(+), 1773 deletions(-)
 delete mode 100644 Documentation/git-filter-branch.txt
 delete mode 100755 git-filter-branch.sh
 delete mode 100755 t/perf/p7000-filter-branch.sh
 delete mode 100755 t/t7003-filter-branch.sh
 delete mode 100755 t/t7009-filter-branch-null-sha1.sh