Make rebase --autosquash work without --interactive, but limit
rebase.autoSquash's effects to interactive mode, and improve testing
and documentation.

Changes from v4:
- Fix amend vs apply backend thinko in commit messages.
- Squash patch 3 for testing into patch 2 and improve the commit
  message.
- No source changes.

Thanks again to Junio and Phillip for their reviews.

Andy Koppe (3):
  rebase: fully ignore rebase.autoSquash without -i
  rebase: support --autosquash without -i
  rebase: rewrite --(no-)autosquash documentation

 Documentation/config/rebase.txt        |  4 ++-
 Documentation/git-rebase.txt           | 34 +++++++++++++----------
 builtin/rebase.c                       | 17 +++++-------
 t/t3415-rebase-autosquash.sh           | 38 +++++++++++++++++++-------
 t/t3422-rebase-incompatible-options.sh | 12 --------
 5 files changed, 58 insertions(+), 47 deletions(-)

-- 
2.43.0-rc2