Add lodash-amd as a JS dependency

As discussed yesterday at the CS meeting and to follow on from #2211 . This PR adds [lodash-amd](https://github.com/lodash/lodash-amd) as an JS dependency. This gives us access to the [wide range](http://lodash.com/docs) of functional utilities the library supplies.

#### Notes
The most important thing to note here is that you can import functionality from the library at a method level and don't have to import the entire thing each time you use it. Require.js will then only compile the dependencies we use in the app.js file and not the whole lib.

#### Example
```JavaScript
define([
    'lodash/arrays/difference',
    'history',
], function(
    difference, 
    History
) {

    var foo = [1, 2, 3, 4, 5];
    var bar = [5,2,10];
 
    var diff = difference(foo, bar);
    // → [1, 3, 4]

    return new History(diff);

});
```

![building blocks](http://stream1.gifsoup.com/view4/2306889/yuuya-buildingblocks-o.gif)

/cc @commuterjoy @jamesgorrie @indeox @ironsidevsquincy @stephanfowler