Calendar remians open after date selection when showTimepicker = false

[spmorganjr]

There's an override to the _selectDate() method that prevents the calendar from closing after selecting a new date. If the timepicker is not enabled then there's no reason to execute this code, it should instead fire the base _selectDate() method.

There's a check for the instance of the timepicker tp_inst, however this is always evaluating as true. Should also be checking for showTimepicker option.

[spmorganjr]

Resolved with pull request #688.