R1:492d047a4925

Improve tokenizer sorting rules

Summary:
Currently, we sort all results alphabetically. This isn't ideal. Instead, sort them like this:

- If the viewing user appears in the list, always sort them first. This is common in a lot of contexts and some "Ben Evans" guy is sorting first on secure.phabricator.com and causing me no end of aggravation.
- If the tokens match a "priority" component (e.g., username), sort that before results which do not have a "priority" match.
- Within a group (self, priority…