Bury click event inside the date picker or calendar

I made a change to stop the propagation of the click event inside the
datepicker/calendar. When the date picker is added to a popover, it gets
added to the DOM as a sibling of the popover as opposed a child element
of the popover div. When a user clicks on a date within the calendar,
the popover closes immediately because the click event is detected as
being outside of the popover. If I bury the click event inside the
datepicker, then the popover stays open and the user can continue
configuring the factor. Once a date has been chosen, I hide the popover.

@bigsley @igorT @ppong