Create wrapper class that takes an OFMessage and allows for direct use in...

Create wrapper class that takes an OFMessage and allows for direct use in other containers where we don't care about the XID of the message. For example, if we want to create a unit test with predictable results but the XIDs are different depending on unit test execution, we can use the wrapper class to guarantee consistency. In the main code, we can more easily compare OFMessages without care for the XID and create cool data structures like caches.