Reflectometric curves cannot be calculated for angles <=0.002*deg

In GUI any value can be set for scan, but simulation points appear only for >0.002195

For scripts python just falls with exception

Invalid scan: minimum value on coordinate axis is negative

In Base/Axis/MakeScale.cpp we create axis with extended range:

newEquiDivision(name, nbins, start - delta / 2, end + delta / 2)