NXP-11044: mark preview action as supporting ajax
NXP-11061: add new 'select_tags' widget to be able to select one or more tags.

Improve the existing 'tagging_widget_template.xhtml' template to make it easier
to select and add new tags to a document.
NXP-11136: remove events queue now that a global default one is used
NXP-11061: cleanup templates