mctools/ncrystal: NCrystal release 0.9.15

This is expected to be one of the final releases before our 1.0.0 milestone release. It consists of developments carried out during the final stages of preparation of the NCrystal publication :smiley:

• Add three new materials, expanding coverage of data library: Uraninite, Aragonite and SiLu2O5.
• Lower default dcutoff value for most .ncmat files to 0.1Aa, in response to validation plots of Uraninite.
• Updated year in copyright notice in all files.
• Laz/Lau file loader now deals correctly with missing lattice_b/lattice_c parameters, and performs sanity checks in all cases.
• Provide convenience functions/methods to Info objects, providing d-spacing of a given hkl value.
• FillHKL use numerically stable summation when calculating structure factors.
• Add NCrystal version printout from the NCrystal_sample component in McStas. Also sanity check the header file and library versions found.
• Add NCDebyeMSD utilities for getting mean squared atomic displacements in the Debye model and use in .ncmat factory (to replace isotropic Debye/Glauber model everywhere for consistency).
• For cosmetic reasons, avoid signed negative zero in atomic positions.
• Minor updates to .ncmat files (mostly cosmetic or rounding of numbers).