Litle: Support passing optional fields in token based transactions

  * Updated existing token based tests to passed optional fields in the options hash.
  * Added missing certification tests for explicit token registration.
  * Updated existing certification tests to use the latest documented data.
  * Added support for processing a credit transaction with a token as well as a previous transaction id (identification).
  * Updated certification specs based on direct feedback from Litle. (some required data was missing).
Merge remote-tracking branch 'origin/litle/allow-card-token-fields-to-be-set-for-token-based-transactions'

Conflicts:
	lib/active_merchant/billing/gateways/litle.rb
	test/remote/gateways/remote_litle_certification_test.rb
	test/remote/gateways/remote_litle_test.rb
	test/unit/gateways/litle/litle_card_token_test.rb
	test/unit/gateways/litle_test.rb