Fix typo from method name
Use #alert helper when refering to flash[:alert]
Remove :error key in controllers

Use flash.alert, the default for errors.
Remove :failure key in controllers

Use flash.alert, the default for errors.
Remove :success key in controllers

Use flash.notice, the default for errors.
Use #notice helper when refering to flash[:notice]
Set "notice" as default css class for successful flash messages
Migrate missing references of flash[:failure] and :success to helper methods
Remove :notice_confirmation key in controllers

Use flash.notice, the default for notices.
Move flash messages to html helper
Use flash_messages helper in custom view

'layouts/flash' does not exist anymore. It was replaced by this helper.
Expect empty flash message when no valid key is given
Render flash messages (using helper) on Devise view

We moved the view logic to #flash_messages helper.
Merge pull request #100 from neighborly/im-remove-duplicated-flash-msgs

Improve use of flash messages