timmolter/XChange — pull request #733 by nimrood (2014-10-30 19:19:49+00:00)
Title: [Poloniex] expose trade response DTO; exception handling

* Made `PoloniexTradeResponse` DTO available via `buy()`/`sell()` raw methods (*will break clients expecting a `String`*)
* Catch non-200 HTTP response via `PoloniexException` on the public API methods
* `PoloniexTradeResponse` & `PoloniexException` were not working correctly together to catch HTTP-2xx API errors
* `PoloniexTradeResponse` is immutable
* Remove Setters -- use `@JsonCreator` constructor
* Throw `ExceptionalReturnContentException` to parse JSON error into `PoloniexException`