Instead of plain strings, each tag is now an object, having:
{ index: 0,
  label: '',
  value: '',
  type: ''
}
adds support for tags of different types
autocomplete modified to support grouping in the list, yelding different tagit types for the input

defaultType argument added to options, default is 'none' - it is the default type for all newly added tags
Merge pull request #90 from AAverin/tag-types

Adds support for types of tags, each tag is now an object, not just plain string