v.6.17.02

A small update, yet an important improvement for the single crystal menu,
as the NUFFT algorithm needed an important improvement for slices with large steps in reciprocal space
and the lanczos filter was improved along the same lines as well

DISCUS
fourier BUG FIX NUFFT did not work properly for large DELTA(hkl) steps
fourier Improved lanczos filter to work in slices along small dimensions == large DELTA(hkl) steps
mmc BUG FIX, site restrictions on atom types at different sites did not work
REFINE
convergence Added a fourth convergence criterion that stops if lambda becomes too large
Improved output of "refine_best.mac and "refine_new.res"