Merge pull request #526 from sutra/develop

Implement parameters support for BTCChina getTransactions.
Delete BTCChinaDepositObject#setDeposits.
Delete BTCChinaGetDepositsRequest#BTCChinaGetDepositsRequest(String).
Implement BTCChina getWithdrawals API method.
Implement BTCChina getWithdrawal API method.
Add support to withdraw LTC for BTCChina.