"tagging" with default select box #597

Such a great project. Thanks for the work!

I'm having some problems though, the "tagging" function does not work for any of the select boxes other than multi-select. Having this feature on the default single select box is pretty important to my use and I'm guessing it's pretty important to most people's use of the plugin.

Does anyone have plans to implement the "tagging" feature for the default select box?