Updates and bug fixes along with code clean-up
- fixes a bug in LeafNodes for FOF searches that can on very rare occasions incorrectly add an entire leaf node to the FOF group.
- Adds the ability to create adaptive KDTrees where leaf nodes are not all the same size (see [https://arxiv.org/abs/2112.05269] for discussion on the adaptive tree, splay and other updates).
- Classes have move and copy constructors, along with
std::sort
functions, speeding up memory management and overall performance.