[#32413] Show Content title in Page Navigation

Added ability to add the title of the next content item to the template.
I didn't change the template to not change existing sites.

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=32413&start=0
Please follow coding standards and always use `{` and `}` for `if ... else` statements. Like in the conditional just above.