#7484: no more <> around addresses in VRFY or EXPN

The RFC doesn't say that they are allowed; apparently many mailers accept
them, but not postfix.  Contributions to this patch were made by Felipe Cruz
and Catalin Iacob.

The changeset also adds additional indirect tests for quoteaddr (null address
and IDNA-encoded address).
diff --git a/Misc/NEWS b/Misc/NEWS
index f444709..3325966 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -34,6 +34,9 @@
 Library
 -------
 
+- Issue #7484: smtplib no longer puts <> around addresses in VRFY and EXPN
+  commands; they aren't required and in fact postfix doesn't support that form.
+
 - Close the call queue in concurrent.futures.ProcessPoolExecutor when
   shutdown() is called, without waiting for the garbage collector to kick in.