Dynamically referencing columns in Squeel

TL;DR:

If you have an ordering scope on a column of your ActiveRecord model, that must appear in the result set of the group clause. You need to get rid of the scope with ActiveRecord::Base.unscoped to get **SomeArModel.group(:some_column)....

To use different Facebook apps for authentication with Devise and OmniAuth:

1. Add a setup method to Omniauth that dynamically sets the client id and secret:

    # config/initializers/devise.rb
    config.omniauth :facebook, nil, nil, setu...