AUI-1444 - demo source formatting

Hey @jonmak08,

Thanks to @mjbradford89, I'd like to submit `TokenInput`. A feature originally inspired by NSTokenField, forked from rgrove's node-token-input, and designed similar to sliptree's tokenfield.

This feature is a candidate replacement for both aui-textboxlist-deprecated and aui-autocomplete-deprecated. Much of the code was left unchanged.

### Issue(s)
* [A user is unable to use the keyboard to access an ac-list if plugged with `tokenInput`](https://github.com/yui/yui3/issues/1913)

#### pull requests
* https://github.com/liferay/yui3/pull/12
* https://github.com/yui/yui3/issues/1915

### Update
This was merged into yui3/dev-master
https://github.com/yui/yui3/pull/1915#event-143994665