-xml contains no indication whether a class is final

The relevant section of the generated XML for this:

```haxe
final class Main {}
```

...looks like this:

```xml
<class path="Main" params="" file="source/Main.hx"/>
```

As you can see, nothing here to indicate that it's a `final` class - I was expecting `@:final` meta, or `final="1"` (like with `interface="1"`). Context: wanted to render this info in dox.