subscription Messagecount should be a readonly property. fixes Azure#61

Currently we have subscription.setMessageCount()  which I feel doesn't make sense.
Also from .net msdn doc this is a readonly property
http://msdn.microsoft.com/en-us/library/windowsazure/microsoft.servicebus.messaging.subscriptiondescription.messagecount.aspx

microsoft-azure-api/src/main/java/com/microsoft/windowsazure/services/serviceBus/models/Subscription.java

@@ -94,11 +94,6 @@ public Long getMessageCount() {
         return getModel().getMessageCount();
     }
 
-    public Subscription setMessageCount(Long value) {
-        getModel().setMessageCount(value);
-        return this;
-    }
-
     public Integer getMaxDeliveryCount() {
         return getModel().getMaxDeliveryCount();
     }