War on whitespace

This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time.  There are a few files that need
to have trailing whitespaces (most notably, test vectors).  The results
still passes the test, and build result in Documentation/ area is unchanged.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-diff-index.c

@@ -23,7 +23,7 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
 	argc = setup_revisions(argc, argv, &rev, NULL);
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
-			
+
 		if (!strcmp(arg, "--cached"))
 			cached = 1;
 		else