Merge branch 'jc/apply' into next

* jc/apply:
  apply --numstat: show new name, not old name.
  Ensure author & committer before asking for commit message.
  Install git-send-email by default
  send-email: address expansion for common mailers
  diffstat rename squashing fix.

diff --cc Makefile
Simple merge

diff --cc apply.c
Simple merge

diff --cc diff.c
Simple merge