Update ember.js todomvc to ember 1.0.0.rc.8

 * Update handlebars to 1.0.0
 * Update ember-data to latest
 * fix linkTo -> link-to
 * actions hash for controller actions
 * use ember computed property instead of *Binding
 * Break main template into partials for readability
 * use ember rc8 from bower
 * Add Todo.TodosView with didInsertElement to focus on new todo field