AFAIK, there is no feature that does this automatically. However, the simplest way would be to edit the inc_functions.asp file, removing the braces in the Smile() and CleanCode functions.
Also you can always install the Categorized Icons MOD. It will allow you to retain the braces and at the same time assign alternate code without braces and will still insert the smilies for you.
actually there is. there is one where the smilies are places on the left when posting a new topic or reply and you can insert them just by clicking on them. just can't remember the name of that mod...