Previously, they were just used to filter out reflections outside the resolution range, and the bins would
be calculated from the resolution limits of whatever was left. Now, the given values are used exactly
for calculating the bins.
If there are large changes in intensity between shells, the R-factor should reflect it.
The old formulation did not have that property. Weak resolution shells would show up
with low R-factors because they contributed very little to the overall R-factor, but
the actual correspondence between intensities could still be very poor.
