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

This updates the todomvc sample app for ember.js to match the most recent version of ember, 1.0.0-rc.8.

 * Update handlebars to 1.0.0
 * Update ember-data to latest
 * linkTo -> link-to, bindAttr -> bind-attr
 * actions hash for controller actions
 * no quotes for property paths in handlebars (only quotes for actual
   strings)
 * use ember computed property instead of *Binding
 * update bower.json to reference ember rc 8
 * views support a container lookup by viewName
 * Use handlebars `input` helper instead of `view` for checkboxes and text fields