Better GAMS precision

GAMS precision (completed)
change gitignore (completed)
Save results + parameters (same parameters, just take previous result)
(TODO)
Check stability (TODO)
Comparing actuals (TODO)
Random numbers scenario generation on/off (TODO)
Check scenario generation (only forecast used or also actual planning)
(TODO)
Forecasts (ARIMA: spot, imbalance, heat demand, wind(historic?), storage
(from heat?)) (TODO)
Change parameters and compare (TODO)