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>

merge-index.c

@@ -25,7 +25,7 @@ static void run_program(void)
 static int merge_entry(int pos, const char *path)
 {
 	int found;
-	
+
 	if (pos >= active_nr)
 		die("git-merge-index: %s not in the cache", path);
 	arguments[0] = pgm;