At some point, you may want to actually throw some settings into Play plugin that the PlayJava/PlayScala plugins would extend/enhance.  

It's possible that someone could do this kind of crazy:

```scala
val dumbProject = project.addPlugins(Play).disablePlugins(PlayJava,PlayScala)
```

Which would mean all the settings people expect when they "hook" a play build won't be there.

Perhaps I'm commenting too early and that's the V2 of this revision?