Provides the Journal Content portlet export and import functionality, which
is to clone the article, structure, and template referenced in the
Journal Content portlet if the article is associated with the layout's group.
Upon import, a new instance of the corresponding article, structure, and
template will be created or updated. The author of the newly created
objects are determined by the JournalCreationStrategy class defined in
portal.properties.
This PortletDataHandler differs from from
JournalPortletDataHandlerImpl in that it only exports articles
referenced in Journal Content portlets. Articles not displayed in Journal
Content portlets will not be exported unless
JournalPortletDataHandlerImpl is activated.