* fixed an error of chosen: placeholder text doesn't display sometimes.

assets/chosen/js/chosen.jquery.js

@@ -400,7 +400,7 @@ This file is generated by `grunt build`, do not edit it by hand.
       _ref = this.form_field.options;
       for (_i = 0, _len = _ref.length; _i < _len; _i++) {
         option = _ref[_i];
-        if (option.selected) {
+        if (option.selected && option.value != '') {
           this.selected_option_count += 1;
         }
       }
@@ -519,9 +519,9 @@ This file is generated by `grunt build`, do not edit it by hand.
       return true;
     };
 
-    AbstractChosen.default_multiple_text = "Select Some Options";
+    AbstractChosen.default_multiple_text = "";
 
-    AbstractChosen.default_single_text = "Select an Option";
+    AbstractChosen.default_single_text = "";
 
     AbstractChosen.default_no_result_text = "No results match";