Fixes typo
GatewayProvider UI.  Wired up the dialog service for configuration editing.
Moves fixed providers back to Core as we don't need the attribute.  Concept work on AuthorizeNet payment provider.
Publicized the SerializationHelper so that GatewayProvider developers can use if for ExtendedData serialization helpers.
More work on the Authorize.Net GatewayProvider
Merge pull request #522 from rustyswayne/1.0.1

Initial work on Authorize.Net PaymentGatewayProvider for an example Plugin Provider.