feat(encoreNav): EN-1450 Move Cloud under Account

**Do Not Merge** - Requires sync with Encore UI and Cloud.

Move Cloud products under Account menu and add directive for switching account users.

![cloud_servers_and_rackerlabs_encore-ui-nav](https://cloud.githubusercontent.com/assets/17910/4849128/7796a006-605f-11e4-8e43-c81a329ab1f6.png)