Bittrex: no assumptions about unknown order fields
Bittrex: no assumptions about unknown order fields

* Order side may not be defined in response so should be reported as such
* Order status should not be assumed to be open by default as in certain cases order status is undefined
* Do not try to calculate various order quantities not present in actual response

ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt