remove superfluous file comments_route.js
update TODO list
create tagged_controller.js
create tagged_route.js
create tagged.handlebars
create tagged_view.js
change the posts controller's index action to accept a tag name as search parameter
add links on the tag names in the post template
add a route for searching posts by tag to router.js
install gem devise
set up devise (except for flash messages)
generate user model via devise
install omniauth-related gems
prettify devise_create_users migration
generate authentication model
migrate DB
generate authentications controller (with preliminary test view)
create twitter initializer
configure ominauth providers in devise initializer
create user.js (model)