Add basic for oauth_application directly link to an account
in initializer/doorkeeper: add config like:

  original_resource_owner do
    # replace by Doorkeeper.find(params[:client_id]).account_access
    Account.first
  end

Conflicts:
	lib/doorkeeper.rb
	lib/doorkeeper/config.rb
Add xframe options for oauth/authorize

Conflicts:
	lib/doorkeeper/config.rb