* Stop shipping hand-written .nxs files. Instead, attempt to auto-generate
.nxs files from all shipped .ncmat files, and where possible ship
those. This is done in order to ensure greater consistency and a lower
burden of maintenance moving forward. During this process a few issues
were found with Wyckoff positions in a few .nxs files, which should now
be fixed by the new procedure.
* Changed dcutoff for crystals with complex unit cells (like yttrium
oxide) from 0.4Aa to 0.25Aa when loading from .ncmat. For all other
.ncmat files in our data library, the value stays at 0.15Aa.
* Fix LCBragg error in case of the double degenerate case where both
neutron and lcaxis are parallel to (0,0,1).
* Faster fillHKL function, in particular for very small dcutoff values.
* The fillHKL function now supports the NCRYSTAL_FILLHKL_IGNOREFSQCUT
environment variable, which can be used to disable the fsquarecut entirely.
* Increased numerical stability in structure factor summation during
PCBragg initialisation.
* Phase out usage of non-standard constants like M_PI.
* Increase MC overlay safety factor slightly for LCBragg scatter generation.
* Improve colors and linestyles in ncrystal_inspectfile script.
* LCBraggRef models use numerically stable summation.