Currently, the help for git filter-branch refers users of --env-filter
to git-commit for information about environment variables affecting
commits. However, this information is not contained in the git-commit
help, but is very explicitly detailed in git-commit-tree.
Signed-off-by: Wesley J. Landaker <wjl@icecavern.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>