MtApi (MT4) and MtApi5 (MT5) version 2.0.1

MT5:
Issue #261: EA MtApi5 get locked/frozen under mutli-symbol optimization mode during backtesting
Issue #262: client.GetQuotes() always returns the first quote recieved
Issue #284: [REQUEST] Add a new method to retrieve all symbols
Issue #290: time_bar, but the period of the bar is unknown.
Issue #291: "OBJECT" methods not working correctly in MT4
Issue #296: CopyRates v2.0 - MetaTrader is null

MT4:
Issue #167: about order's comment is null
Issue #241: CloseTime is not available in OrderClose
Issue #246: Change iBands function : deviation parameter int -> double
Issue #284: [REQUEST] Add a new method to retrieve all symbols
Issue #291: "OBJECT" methods not working correctly in MT4

MtService: fixed crash on disconnect last expert in MT terminal