Choose better sorting and priority queue algorithms

[pczarn]

• [ ] Gather statistics about the order of item arrays to better choose algorithms.
• [x] Implement an unstable, O(n log n) time, constant space sorting algorithm that work fast on small and medium-sized arrays -- probably a combination of pattern-defeating quicksort and insertion sort.
• [ ] Implement a special case for the priority queue that works fast on small arrays of tiny elements. For example, on up to 32 byte-sized elements.

[pczarn]

The Rust standard library already uses efficient sorting algorithms.