A thin wrapper around https://github.com/hakimel/Ladda .
If you copy files from the interwebs into your project, kittens die.
Do this instead (in your Gemfile):
gem "ladda-rails", :git => "git://github.com/Promptus/ladda-rails.git"
In your application.css:
*= require ladda
In your application.js:
//= require "spin"
//= require "ladda"
If using jquery, add this line:
//= require "ladda.jquery"
We'll try to keep this project's version numbers the same as those from Ladda.