Use of build in xml builder.

[akDeveloper]

An xml builder was introduced in 1.1.0 version.
Every gateway that communicate with xml (except Soap), should use this build-in xml builder.

List of gateways that use xml:

• AuthorizeNet (ARB) Moved to v2.0 Leading gateways support v2.0 #66
• BridgePay
• Eurobank (Is deprecated so will not have to convert it)
• HsbcSecureEpayments
• Iridium
• Moneris
• Payflow
• WorldPay