Jquery plugin

Jquery plugin.

Since jquery's model is that every module adds functionality to the $ symbol (i.e. the variable returned by the jquery/core module), I opted to allow listing multiple modules for the plugin, ex:

 ```js
require(["requirejs-dplugins/jquery!attributes/classes,effects"], function ($){
    ...
    $(myNode).addClass("selected");
    $(myNode).animate(...);
});
```

Other things to note:

jQuery code is in jquery/src dir by default, so plugin is mapping to that directory automatically.   Seems a bit weird.

This PR also includes some other enhancements:

1. standardizing the test directories into unit/ and functional/ (like other projects)
2. upgrade to intern 2.1

TODO:  automate build test (webdriver load app.html and check output)

We discussed that offline but here are my additional points for everyone to consider:

1. Even if deploying to WebServer un-needed code is mostly un-problematic, there is always the "mobile" case where things happened to be deployed on the device while un-needed.
1. This project is not just for the delite/deliteful work but supposed to be usable by other people. Part of those other people some already complained about external dependencies for such a "small" project and I think they would not like to see more added while they don't need them.
1. Honestly I don't think the consuming project adding:
  "jquery": ">=2.1", to their bower.json is problematic. They are the ones using jQuery, so they should be the one picking the version they want not us.
1. Finally in a lot of case people will just use the single down jquery file and actually don't even need that.