Merge sort: Initial test with smaller size
Bug fix: Make sure to use the loop index for the array in merge sort.
Initial working version of merge sort.
Merge sort implementation is _not_ recursive, change its function name.
Cleanup comments
Rename test since merge sort is not recursive
New test: EfficientSorts, MergeSortMultipleSizes
Cleanup
Bug fix merge sort for off number of elements
Optimization: do nothing if array size is one.