All you need to do is to download this dll Epinova.Adapters and add it to your bin folder.

In your App_Browsers folder you should find the AdpaterMappings.browser file. In this add the following line:

<adapter controlType="EPiServer.Web.PropertyControls.PropertyCategoryControl" adapterType="Epinova.Adapters.PropertyCategoryAdapter" />

After this your category list should go from this:

to this:

Enjoy! :)