active_merchant: fix gateway configuration

Passing ssl_strict = false wasn't honored for instance.

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
active_merchant: enhance handling of payment method types

* Store the cc_number in the database when not using tokenization (mostly for testing)
* Retrieve the full credit card if no external token was specified
* Support placeholder rows (no cc information, no token)
* Return ccFirstName, ccLastName and ccNumber in payment method properties

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
active_merchant: switch all payment method fields to varchar

This lets us support proprietary token formats used instead of the
PAN for instance (proxy tokenization).

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>