Fix problem when input with Chinese input method

Similar problem with:
Change event fires too many times when inputing Chinese characters
facebook/react#3926

src/ajax-chosen.coffee

@@ -29,16 +29,25 @@ do ($ = jQuery) ->
       @search_field = @element.next('.chosen-container')
         .find(".search-field > input, .chosen-search > input")
 
+      @ignore_input = false
       @register_observers()
 
     register_observers: ->
+      @search_field.on "compositionstart", (evt) =>
+        @ignore_input = true
+        return
+      @search_field.on "compositionend", (evt) =>
+        @ignore_input = false
+        @update_list(evt)
+        return
       @search_field.keyup (evt) => @update_list(evt); return
       @search_field.focus (evt) => @search_field_focused(evt); return
 
     search_field_focused: (evt) ->
       return @update_list(evt) if @options.minTermLength == 0 and @search_field.val().length == 0
 
     update_list: (evt) ->
+      return if @ignore_input
       # This code will be executed every time the user types a letter
       # into the input form that chosen has created