Make updatename non-blocking

Example of making ```updatename``` use callbacks to avoid blocking calls

Ideally ```addchange``` and ```findchange``` would also be made non-blocking, which would mean nesting the callbacks, e.g.
```perl
$self->updatename(sub {
    # ...
    $self->addchange(sub {
        # ...
        $self->findchange(sub {
            # ...
        });
    });
});
```

That will get messy quickly (sometimes unavoidable) but might be cleaned up by refactoring (e.g., possibly making updatename, addchange and findchange a single "helper" method with a single callback, moving the complexity out of the controller and into the helper module)