Removing "unsafe" way of defining redirects inside of the route or resource definitions.

This PR **removes** the ability to define a redirect like so:
```js
this.route('foo', { redirect: 'bar' });
```

and instead **must** be defined on the router object like so:

```js
var Router = Ember.Router.extend({
  location: config.locationType,

  redirects: {
    'foo' : 'bar'
  }
});
```