Name based on relative paths in AMD transpiling

See [this Gist](https://gist.github.com/thomasboyt/5703635) for rationale. tl;dr is that 

```js
import { something } from "./foo/bar";
```

in a file called "lib/foo.js" will now AMD transpile to

```js
define("lib/foo",
  ["lib/foo/bar", exports],
  function(__dependency1__, __exports__) {
    "use strict";
    var something = __dependency1__.something;
  });
```

allowing for relative pathing in your source being properly renamed when compiled to AMD.