Option to gaurantee order of directory listings when adding to queue

[AllenJB]

I searched an already found issue #4416 on this issue. I understand that there would be additional overhead when doing this, but I would like the option to be able to guarantee the order of directory contents when adding to the queue.

I would suggest having this as an option that is not enabled by default - this way people like me who don't mind the overhead, perhaps because they don't queue deep directory structures often can choose to enable it. A warning could be added alongside the option if the overhead is particularly significant.

[Icy]

Updated #4416 with my two-cents AllenJB.