feat(ng-let): ng-let directive added for async convenience
feat(ng-let): ng-let directive added for async convenience

fabric8io/fabric8-planner,fabric8io/fabric8-ui,fabric8io/fabric8-planner,almighty/almighty-ui,almighty/almighty-ui,fabric8-ui/fabric8-ui,fabric8io/fabric8-ui,fabric8io/fabric8-ui,fabric8-ui/fabric8-ui,fabric8io/fabric8-ui,fabric8-ui/fabric8-ui,almighty/almighty-ui,almighty/almighty-ui,almighty/almighty-ui,fabric8io/fabric8-planner,fabric8-ui/fabric8-ui,fabric8-ui/fabric8-ui,fabric8io/fabric8-ui,fabric8io/fabric8-planner,fabric8io/fabric8-planner