7.x 4.x 67 add confirm form to gateway settings

Adds a javascript confirm popup to the fundraiser payment method settings submission, in order to communicate to site admins that they really ought not to accidentally disable their transactions with a bad config option.

Logs the user, timestamp, gateway name, new settings values and the original settings values to  the db, and provides a view of the log accessable at admin/springboard/reports/gateway-settings-log