whatsnew: Message.set_param *replace*, Policy.content_manager.

Also cleaned up the email section and fixed some markup bugs in the
email docs.
diff --git a/Doc/library/email-examples.rst b/Doc/library/email-examples.rst
index 294e131..cbbcb78 100644
--- a/Doc/library/email-examples.rst
+++ b/Doc/library/email-examples.rst
@@ -40,8 +40,10 @@
 .. literalinclude:: ../includes/email-alternative.py
 
 
-Examples using the Provision API
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.. _email-contentmanager-api-examples:
+
+Examples using the Provisional API
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Here is a reworking of the last example using the provisional API.  To make
 things a bit more interesting, we include a related image in the html part, and
 we save a copy of what we are going to send to disk, as well as sending it.