+JH/35 Require SINGLE_DH_USE by default in OpenSSL (main config option
+ openssl_options), for security. OpenSSL forces this from version 1.1.0
+ server-side so match that on older versions.
+
+JH/36 Fix a longstanding bug in memory use by the ${run } expansion: A fresh
+ allocation for $value could be released as the expansion processing
+ concluded, but leaving the global pointer active for it. Possibly
+ involved in Bug 1778.
+
+JH/37 Bug 1769: Permit a VRFY ACL to override the default 252 response,
+ and to use the domains and local_parts ACL conditions.
+