- Add a Features service for examining feature flags on the frontend
- Add a directive (quay-requires) that matches feature flags and, if any one does not match, removes the element from the DOM
- Add a directive (quay-show) that injects the features into the scope so that expressions of the form "Features.BILLING || something" work out of the box to show/hide the element
- Add a directive (quay-classes) that allows for setting of CSS classes on an element based on feature expression(s) such as {"!BILLING": "active"} (e.g. the BILLING flag is set to false, add the class "active".
