Fixed cancelOrder queries.
Issue #74 - fixed  bound on wazne_od field in queries in wykonaj_zlecenie_* procedures.
The cancel order request now returns failure only if there are any errors arisen from the queries. Unfortunately there is no way (that I found/ know of) to check if any records were deleted with QSqlQuery. This could be achived by creating stored procedure, but I don't think it such a big of a deal as user can't deleted order which he doesn't own (he gets confirmation, but that's about it).
Issue #64 and #62 - Partial integration of DataHub and TradingServer. Added support for orderChange and orderCompleted notifications in TradingServer.
Issue #69 - Fixed order_change notifications to match specs given in wiki - user should know the amount of stock that have been traded away.