Stable sort algorithm

[KidkArolis]

Would be great to replace the native sort function with a stable algorithm.

Currently if options.sort is false, then

search.items.sort(function(a, b) {
  return b.score - a.score;
});

Messes up the original order of the array in certain browsers due to non stable native sort.

[KidkArolis]

Hm, I see that's trickier than I thought, because all options in selectize and sifter are stored as Objects, not arrays, so the order is not guaranteed anyways.. I guess I have to manully add "index" option to my items and sort by that.

[KidkArolis]

My usecase in selectize was fetching an autocomplete list from the server where order is important (most relevant items at the top). Now if I type a search query, I want to filter down the list, but I don't want to change the order. I mistakingly thought sifter would still be useful for filtering out the items that don't match, but really I just need to supply my own score function that returns the index of the item and also checks (via indexOf or a fuzzy way) whether the search query matches the item.