datepicker: getDate function now gets date whether or not datepicker is opened (fixes #2832)

ui/demos/functional/datepicker/debug.html

@@ -14,7 +14,7 @@
 		
 		<script type="text/javascript" charset="utf-8">
 			$(function(){
-				$('#testing').datepicker({ yearRange: '-80:+0' });
+				$('#testing').datepicker();
 			});
 		</script>
 	</body>

ui/source/ui.datepicker.js

@@ -254,6 +254,9 @@ $.extend(Datepicker.prototype, {
 	           Date[2] - the current dates for a range */
 	_getDateDatepicker: function(target) {
 		var inst = this._getInst(target._calId);
+		if (inst) {
+			inst._setDateFromField($(target)); 
+		}
 		return (inst ? inst._getDate() : null);
 	},