AUI-1814

Hey @zxdgoal,

Attached is an update for https://issues.liferay.com/browse/AUI-1814.

We need a few updates for this pull request to be merged in:

1. Add an entry in README.md with the AUI ticket number and description.
2. Add unit test to https://github.com/liferay/alloy-ui/blob/master/src/aui-datepicker/tests/unit/js/tests.js regarding the additional trigger you added.

This change will be added to liferay-portal/master and then we can backport it to alloy-ui/2.0.x for liferay-portal-ee/ee-6.2.x.

Please let me know if you have any questions.  Thanks!