Component support

This adds support for [component](https://github.com/component/component) i.e.:

```
var foo = angular.module('foo', [
  require('angular-ui-router'),
  ...
```
I've updated:
- `grunt` `concat`'s "banner" to include code to support `commonjs`.
- `grunt` `prerelease` to ensure `component.version` is synced up.
- `readme.md` to include `component` instructions.

Let me know how to improve this or if its good to go. Note that I have not cut an actual release which appears to be something inappropriate to do myself.

Thanks.