add a note about the frame refactor in the readme

README.md

@@ -11,6 +11,11 @@ Project Website: http://gocql.github.io/<br>
 API documentation: http://godoc.org/github.com/gocql/gocql<br>
 Discussions: https://groups.google.com/forum/#!forum/gocql
 
+Production Stability
+---------
+The underlying framing code was rewritten as part of #339 and as such may have
+unforseen bugs. If you run into a bug related to wire framing, please raise a ticket and we will try to resolve this as soon as we can. If you require a stable version to pin your production app against, we have tagged the previous stable version in source code, so you can build against this. The tag is called 1st_gen_framing (180456fef0a3c6d02c51dc7211f49b55e9315867). This note will be removed as the new generation framing code base matures
+
 Supported Versions
 ------------------