js.lib.Thenable<js.Thenable.T> vs js.lib.Promise.Thenable<Dynamic>

Hi Guys... I'm loving Haxe4 RC3. I've just noticed that the deprecation warning for:

```bash
js.Promise.Thenable
```
States
```baseh
This typedef is deprecated in favor of js.lib.Thenable
```
But really you need to use
```
js.lib.Promise.Thenable
```

I don't know if I'm right or not so I don't want to try to submit a PR until someone confirms this please.

Thanks