updated for version 7.4.609
Problem:    For complicated list and dict use the garbage collector can run
            out of stack space.
Solution:   Use a stack of dicts and lists to be marked, thus making it
            iterative instead of recursive. (Ben Fritz)
diff --git a/src/version.c b/src/version.c
index 8e26439..36d701e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    609,
+/**/
     608,
 /**/
     607,