Improvements Payment Methods

[Wouter0100]

With the intro introducion of Payment Methods, the ability to better integrate a wide variety of payment methods has gradely improved. Unfortunatly though, still there are some add choices that I'd want to pointpoint. This is holding me back from moving my WHMCS Mollie Recurring gateway to the Payment Methods option in WHMCS.

Rename `Add New Credit Card` to `Add New Payment Method` on the Payment Methods page.
Why should this option be called Credit Card? It may not nessesary add an actual Credit Card, it could also be a Bank Account (or some sort of account with money, like PayPal). By renaming this field, gateway developers have a wider variety of options of implementing this.

I also discovered the `_localbankdetails` method, but this adds a `Add New Bank Account` option - but only allows local input of non-SEPA accounts, something that a SEPA Direct Debit system has no use for. Renaming the Credit Card button to Payment Method would make this Bank Account button absolete as it would allow the developer to create a custom form to implement this.

Different capture intervals for Bank Accounts and Credit Card (or let the gateway provide the interval)
As far as I've found, Bank Accounts also apply to the same interval as Credit Cards currently, as configured with this option. For Bank Accounts, this is far from useful as it would normally take way longer. The ideal implementation would be that every gateway is able to provide it's own delays, depending on the Pay Method. This way, I'm able implement both a Credit Card and a Bank Account Pay Method in the same gateway - as it's processed by the same provider and with the exact same service/API's.

As a workaround, I've implemented the CapturePayment API-call on custom intervals, but this is far from ideal.