Use JSON as default serialization format

Author: codemasterover9000

user/src/com/google/gwt/user/client/rpc/impl/AbstractSerializationStream.java

@@ -47,7 +47,7 @@ public abstract class AbstractSerializationStream {
   /**
    * The current RPC protocol version.
    */
-  public static final int SERIALIZATION_STREAM_VERSION = 7;
+  public static final int SERIALIZATION_STREAM_VERSION = 8;
 
   /**
    * The oldest supported RPC protocol version.