Some bug fixes and improvements.
Added method for account check.
Added account connected check and changed LOT_SIZE to 1000(minimum for
Dukascopy)
Performance improvement for asset name lookup; saving asset name in a
map avoids constructions on every BrokerAsset call.
Using assetNameToInstrumentMap where possible.
Added GET_MINLOT and GET_TYPE to BrokerCommand.
Order ID start value moved to configuration.
Created logger class for convenient global zorro logging.
Added a utility class for Instrument.
Changed logger calls.
Removed no longer needed constructor argument.
Added account info class.
Created history handler class.
Moved the logger callback to ZorroLogger.
Minor improvement and fixes.
Extraced method for offline times retreival.