Expands the *Amount parameters in the FPS requests.

I want to resolve issue #2 where TransactionAmount wasn't accepting the required Value and CurrencyCode fields.

TransactionAmount, RefundAmount and SettlementAmount where not being expanded out to include the required Amount fields. Expanded them out to include Value and CurrencyCode sub fields required by Amount fields. This impacts the Pay/Refund/Reserve/Settle/SettleDebt/WriteOffDebt calls.