Use deep copy when cloning settings. Fixes #723

Author: Tomas Kirda

src/jquery.autocomplete.js

@@ -70,7 +70,7 @@
         that.isLocal = false;
         that.suggestionsContainer = null;
         that.noSuggestionsContainer = null;
-        that.options = $.extend({}, Autocomplete.defaults, options);
+        that.options = $.extend(true, {}, Autocomplete.defaults, options);
         that.classes = {
             selected: 'autocomplete-selected',
             suggestion: 'autocomplete-suggestion'