For non-varargs tradeHistory method only TradeHistoryParamCurrencyPair
needs to be implemented.
startdate and enddate are optional parameters in the allmytrades
message, if null is supplied, do not populate these fields on request.
This allows for a more flexible use of TradeHistoryParams.
Implement TradeHistoryParams based query.
Implement TradeHistoryParams based query.
Merge pull request #779 from ww3456/develop

TradeHistoryParams changes for Poloniex, Cryptsy and Bitfinex