Instead, expect the data to be given in the desired order. Completion
functions should sort their data _if_ they want it sorted in the
completion. This has a few implications:
- {book,quick}marks appear in the same order they do in the text file.
This means users can rearrange their mark files for custom sorting.
Fixes#2354
- Sessions are sorted as they appear in the session manager
- Tabs are sorted numerically, not alphabetically (Fixes#2883)
Note that prefix-based filter sorting is still performed, so items
starting with the filter pattern come first.
6e025c1bb0