app/js/app.js: added ui.state & ui.router modules
app/js/app.js: added ui.compat & ui.bootstrap as dependencies
app/js/router.js: rewrote routes using ui.state

* using $urlRouterProvider & $stateProvider instead of $routeProvider

* no idea why ui.state isn't used as dependency in ui-router example
homepage.us: updated with the ui-view directive
router.js: fixed missing semicolons.