audit small applets and mark some of them as NOFORK.

Put big scary warnings in relevant places.

libbb/make_directory.c

@@ -22,11 +22,10 @@
  * val.  Otherwise, pass -1 to get default permissions.
  */
 
-#include <errno.h>
-#include <unistd.h>
-#include <sys/stat.h>
 #include "libbb.h"
 
+/* This function is used from NOFORK applets. It must not allocate anything */
+
 int bb_make_directory (char *path, long mode, int flags)
 {
 	mode_t mask;