Online event rego receipt - no credit card details shown

The default TPL for event registration uses $contributeMode to decide whether to show Credit Card details.

There are 3 issues here.
1) $contributeMode is set to NULL while the TPL expects it to be 'direct' or some other value. This stops the TPL logic working.
2) The credit_card_number is not munged. This is a security issue for the registrant.
3) The credit_card_exp_date needs to be converted from an Array to a date string, otherwise the word "Array" is displayed instead of the date.