ExchangeAmountsCalculator computes deposit amounts
Move split computation to the amounts calculator
Make seller pay the bitcoin fees
Remove unused mockito imports
Introduce the concept of net/gross bitcoin to exchange
Introduce the concept of net/gross fiat to exchange
Simplify deposits information in Exchange.Amounts
Include progress in StepAmounts
Remove Exchange.Amounts.transactionFee
Use the production OKPay endpoint in production

The reference config of `coinffeine-gui` must provide the endpoint of the
production OKPay server.
Merge pull request #229 from apoloval/task/cf-32

Persist bitcoin wallet in file
Update IT
Merge pull request #231 from apoloval/fix/WrongOkPayEndpoint

Use the production OKPay endpoint in production
Merge pull request #230 from sortega/sam_pays_btc_fees

Make seller pay all bitcoin fees