Add tests for extra headers in format-patch
Add tests for extra headers in format-patch

Presently, it works with each header ending with a newline, but not
without the newlines.

Also add a test to see that multiple "To:" headers get combined.

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