patch 9.0.0411: only created files can be cleaned up with one call

Problem:    Only created files can be cleaned up with one call.
Solution:   Add flags to mkdir() to delete with a deferred function.
            Expand the writefile() name to a full path to handle changing
            directory.

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    411,
 /**/
     410,
 /**/