# apostrophe-video-fields (browser)
# Methods
# addFieldType()
# populate(object, name, $field, $el, field, callback)
# convert(data, name, $field, $el, field, callback)
# preview($fieldset, value, field)
Preview the given value. Also acts as a validator by updating
the valid jquery data attribute of the fieldset to true or false
after it clears the busy attribute.