no difference between t_forecastLengthUnchanging and t_forecastLengthDecreasesFrom
Current init files have two parameters t_forecastLengthUnchanging
and t_forecastLengthDecreasesFrom
that are both used only in following lines
// Determine the necessary horizon for updating data
option clear = tmp;
tmp = max( mSettings(mSolve, 't_forecastLengthUnchanging'), mSettings(mSolve, 't_forecastLengthDecreasesFrom') );