package support in generator tasks

e.g.

```
./skinny g scaffold:jade blog.entries blog.entry title:String body:String
```

will generate

- src/main/scala/controller/blog/EntriesController.scala
- src/main/scala/model/blog/Entry.scala
- src/main/webapp/WEB-INF/views/blog/entries/*.jade
- src/test/scala/controller/blog/EntriesControllerSpec.scala

And appends required settings to existing files.