Changed db column(cclastfour) as refundinfo.

Changed db column(cclastfour) as refundinfo.

Because this field will be used to refund both cc and echeck.
Business checkings can be refunded, too; so mark as 1 this field for business checkings.
That is; refundinfo: is last four digit for credit cards, business checking for echecks.

Merged from MOODLE_17_STABLE.