Log Message:
Update ruby-jquery-rails20 to 2.1.2.

## 2.1.2 (06 September 2012)

  - Updated to latest jquery-ujs
    - required radio bugfix
  - Updated to jQuery 1.8.1

## 2.1.1 (18 August 2012)

  - Updated to latest jquery-ujs
    - ajax:aborted:file bugfixes

## 2.1.0 (16 August 2012)

  - Updated to latest jquery-ujs
    - jQuery 1.8.0 compatibility
  - Updated to jQuery 1.8.0
  - Updated to jQuery UI 1.8.23

## 2.0.3 (16 August 2012)

  - Updated to latest jquery-ujs
    - created `rails:attachBindings` to allow for customization of $.rails
      object settings
    - created `ajax:send` event to provide access to jqXHR object from ajax
      requests
    - added support for `data-with-credentials`