HBX-1225 Proxy class should be used for referring property declaration

Property type referencing a PersistentClass should be its proxy, if it has one as Hibernate will attempt to set the property with an instance of the proxy, that is not an instance of the property type until the proxy is resolved.

I've resolved this issue by implementing the approach noted in a comment in JavaTypeFromValueVisitor: should get the cfg and lookup the persistenclass.

So JavaTypeFromValueVisitor now needs to know the Configuration, so it can look up PersistentClasses. This means that Cfg2JavaTool needs to know the Configuration. There are a few classes that use Cfg2JavaTool, but they all had pretty easy access to Configuration, so I passed it along.

The ConfigurationNavigator also refers to Cfg2JavaTool but wasn't _so_ easy to pass Configuration through, so I've left it not doing it. This does not cause a problem for this case.