cleanups: ensure that git-compat-util.h is included first

CodingGuidelines states that the first #include in C files should be
git-compat-util.h or another header file that includes it, such as
cache.h or builtin.h.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

bulk-checkin.h

@@ -4,8 +4,6 @@
 #ifndef BULK_CHECKIN_H
 #define BULK_CHECKIN_H
 
-#include "cache.h"
-
 extern int index_bulk_checkin(unsigned char sha1[],
 			      int fd, size_t size, enum object_type type,
 			      const char *path, unsigned flags);