Use diff_tree() directly in making cover letter
Use diff_tree() directly in making cover letter

Signed-off-by: Daniel Barkalow <29008086f408d0a471729b0d8667fa72ead76296@iabervon.org>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git