AMQP-302 - Remove Warnings During Build with JDK7

* Add JavaDoc links to build.gradle
* Make deprecation message in *FederatedExchange* more expressive (Add affected version)

AMQP-302 - Code Review Changes

spring-erlang/src/main/java/org/springframework/erlang/connection/SingleConnectionFactory.java

@@ -229,7 +229,7 @@ public class SingleConnectionFactory implements ConnectionFactory,
 		classes.add(Connection.class);
 		return (Connection) Proxy.newProxyInstance(
 				Connection.class.getClassLoader(),
-				classes.toArray(new Class[classes.size()]),
+				classes.toArray(new Class<?>[classes.size()]),
 				new SharedConnectionInvocationHandler(target));
 	}