Towards more straightforward z-score calculations
Minor changes:
- Samples in null set reference (required for z-scores) are no longer median centered. This procedure had a negligible effect, yet was inconsistent (as it was only applied to autosomes).
- Instead, actual z-scores are calculated as (X-u)/sd, instead of X/sd in previous version.
- Terminology update from monoploid/diploid/triploid to 1n/2n/3n, which is more appropriate when referring to single aberrations.