title: How to modify jquery tag-it plugin: limit number of tags and only allow available tags
body: <p>how to modify the tag-it ui plugin <a href="https://github.com/aehlke/tag-it" rel="noreferrer">https://github.com/aehlke/tag-it</a> (version v2.0) so it only allows selection of x numbers of tags and how to allow only tags that are in the "availableTags-option"?</p>
  
  <p>this question (or the first part of it) is already asked and aswerd in the past but for previous version of the plug-in.</p>