- writeDataIntervalMinutes should now work as intended.
- Added minimumGlobalSignalMinutes. This will determine how long a BNF signal will be kept alive. The default is 30 to continue a signal even if there is an error in a web request.
For SP500 or tick density the minimum duration will be the minimum between minimumGlobalSignalMinutes and SP500MinimumSignalMinutes (or tickDensityMinimumSignalMinutes for tick density).

- Corrected a bug that could lead to a wrong tick density value for certain currencies.
- Change to TimeGMT() else it would create a signal all weekend if there was a trigger Friday.