Planned improvements

1. The project website boasts about performing k-nearest-neighbours searches in n log k time. Without any initial binning, this could, in fact, be done in only n time if the selection algorithm were updated to something based on a quicksort. Code already exists in the repository. Tests show a significant speed improvement.
2. Updating the n-fold cross-validation program to work with pdf estimation and non-linear regression.
3. There may be duplicates in the border samples, especially with small datasets. This needs to be fixed.