Proposal: Move out DoneJS Dependencys to Generator

I Engineered a lot on new versions of the donejs cli and donejs. As a passionated developer, I determined that the dependencies for `donejs add app` shouldn't be in this project at all. They should get added to the generator. This way projects are easy updatable and all that via installing a new generator.

This way we could move out all the code to other generators. For example, parts like `donejs add app`, `donejs add plugin` and that to the generator we give it a bin "add". This way we can strip out all parts from donejs cli that have to do with the generator and can then do donejs add and it will run the add binary from the generator-donejs.
This way we are more cool more stable and easyer update able.
We can also then implement other alternative installers like Yarn as well.

greetings.

Hope that makes sense :D