[PATCH] git-diff-*: --name-only and --name-only-z.

Porcelain layers often want to find only names of changed files,
and even with diff-raw output format they end up having to pick
out only the filename.  Support --name-only (and --name-only-z
for xargs -0 and cpio -0 users that want to treat filenames with
embedded newlines sanely) flag to help them.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff.h

@@ -59,6 +59,8 @@ extern int diff_queue_is_empty(void);
 #define DIFF_FORMAT_MACHINE	1
 #define DIFF_FORMAT_PATCH	2
 #define DIFF_FORMAT_NO_OUTPUT	3
+#define DIFF_FORMAT_NAME	4
+#define DIFF_FORMAT_NAME_Z	5
 
 extern void diff_flush(int output_style);