install backbone-on-rails and marionette-rails
remove Bower
rewrite to Backbone.js (WIP)
Revert "reorder gems"

This reverts commit dc05bf9ca883e283fb09c081755f54963312542c.
Revert "remove coffee-rails"

This reverts commit 52f125104e894e86540264027c994411cdcffc08.
Revert "update Rails"

This reverts commit d52d4151930487f42f74613bd39f04dd25c19482.
Merge branch 'refs/heads/master' into backbone

Conflicts:
	Gemfile.lock
update rails
remove marionette-rails
reorder gems
remove marionette from application.js
add handlebars_assets
Rewrite to Backbone.js: render posts
Rewrite to Backbone.js: add post
bump jbuilder
Rewrite to Backbone.js: render comments
Fix a bug that users can't post
Add a feature that users can submit a comment to posts
Remove unused code
Add ifIsUserSignedIn helper