Add de-namespaced Booking class. Stupid copy paste, probably to be dropped again.
user
```ruby
class Booking < ActiveRecord::Base
  validates_presence_of :debit_account, :credit_account, :title, :amount, :value_date

  belongs_to :debit_account, :foreign_key => 'debit_account_id', :class_name => "Accounting::Account"
  belongs_to :credit_account, :foreign_key => 'credit_account_id', :class_name => "Accounting::Account"

  belongs_to :reference, :polymorphic => true

  # Standard methods
  def to_s(format = :default)
    case format
    when :short
      "#{value_date.strftime('%d.%m.%Y')}: #{credit_account.code} / #{debit_account.code} CHF #{sprintf('%0.2f', amount.currency_round)} "
    else
      "#{value_date.strftime('%d.%m.%Y')}: #{credit_account.title} (#{credit_account.code}) an #{debit_account.title} (#{debit_account.code}) CHF #{sprintf('%0.2f', amount.currency_round)}, #{title} " +
        (comments.blank? ? "" :"(#{comments})")
    end
  end

  def accounted_amount(account)
    if credit_account == account
      return amount
    elsif debit_account == account
      return -(amount)
    else
      return 0.0
    end
  end

  # Hooks
  after_save :notify_references

  private
  def notify_references
    reference.booking_saved(self) if reference.respond_to?(:booking_saved)
  end
end
```
assistant