Update Gemfile and config files
Update routes.rb file, replace 'match' with 'get'
Replace 'attr_accessible' with strong parameters to prevent mass assignments attack
Bundle update
Remove useless configuration
Add markdown offical page link
Add client_side_validations gem
Remove client_side_validations and cancan
Replace omniauth with Persona
Make Persona verifier service's paramter audience configurable
Fix ajax error callback function
Add Rspec for testing
Refactor model test for article and user
Update tag_path to tagging_path
Update jquery.autogrowtextarea plugin
Add feature and controller tests
Merge branch 'rails4'