AppConfig, XML and Form design updates

App.config: The HostList's now support Mercury FECERT and the In-Store
NETePay. The MerchantID list has been expanded to support G2 and FECERT
processing. The SecureDevice and PadType have been updated to reflect
the more common devices.

XML: I removed all NVP that are not required. I also added FSA, ZeroAuth
and (VoidSale) Reversal

Form Design: The HostList have been converted from Text to ComboBox