patch 7.4.1407

Problem:    json_encode() does not handle NaN and inf properly. (David
            Barnett)
Solution:   For JSON turn them into "null".  For JS use "NaN" and "Infinity".
            Add isnan().

src/version.c

@@ -748,6 +748,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1407,
 /**/
     1406,
 /**/