create posts_index_controller
adapt posts.feature to new post sorting order
display posts in order in the posts index template
change seeds.rb so that there's at least 1 second between the creation of 2 posts
update TODO list
call method load_and_authorize_resource in the comments, posts and users controllers (commented out in the posts controller's case)
add a redirect in case of CanCan exception to application controller
make the computed property postsWithTag watch the content of the posts_index_controller
create partial _messages for handling flash messages
render partial _messages in devise layout
correct indents in template tagged
change warning message in posts_new_controller
make CanCan rules available in ember.js (preliminary solution)
add new comment form to post template