Provide option to Clear calendar

[Steve Kerr]

I am using this component as a part of an advanced search and I'm unable to find any way to clear the selection. I've tried implementing a 'clear calendar' button, but it seems the selected value is stored pretty deep in the code and I can't seem to get rid of it. I've tried destroying the datepicker and re-creating it but it still remembered the selected date.

If we could have an issue to de-select the selected date it would be very useful.