Bug: Plugin used to break on empty strings.

Someone reported an issue about this plugin.
I'm publishing a fix here so others can benefit as well.

sorting/date-eu.js

@@ -19,6 +19,8 @@ jQuery.extend( jQuery.fn.dataTableExt.oSort, {
 	"date-eu-pre": function ( date ) {
 		date = date.replace(" ", "");
 		var eu_date, year;
+		
+		if (date == '') return;
 
 		if (date.indexOf('.') > 0) {
 			/*date a, format dd.mn.(yyyy) ; (year is optional)*/