Trigger changeDate event when manually updating the field.

Also adds `clearDate` event when the field is manually cleared.
Fix zh-TW

More appropriate use of Traditional Chinese habit
Fix
Cleanup
Only trigger manual entry changeDate when date changes
Merge pull request #573 from adamjacobbecker/patch-2

Trigger changeDate event when manually updating the field.
Document clearDate event
Add some missing change events to value setters

Fixes #567
Merge pull request #584 from FrankWu100/master

Fix zh-TW