Log when we can't find a specified property dependency.
It's time for an editable DateRange object.

Checkpoint.
Document that the annotation properties are checked on the setter.
Clean up annotations, document.
Allow nullable dates to have a customized display string.
Have nullable properties rather than separate boolean props for enabling.
Default the nullKey to m.null_value.
Just use the default null translation.
Press ENTER to canonicalize the value, like losing focus.
Reweight.