Fix blur and sort behavior for autocomplete

Summary:
Ref T10163.

• If you click a result, we get a blur before your click hits, and deactivate before the click can work. Instead, wait before responding to blur.
• Use the standard sort handler which puts unixnames over human names. Also use the standard filter which deals with disabled users not matching unless they're the only match.

Test Plan:

• Clicked a result, got a replacement.
• Named myself "dog dog", typed "@dog", user "@dog" was now first match despite me being "@admin".
• Used normal typeaheads to make sure I didn't break sort handler.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10163

Differential Revision: https://secure.phabricator.com/D15031