Converts shortcodes for page links and documents from SS2.4 to new SS3.0 notation
Only works for MySQL databases for the moment
Usage:
run sake dev/tasks/ShortcodeConverterTask
What does it do? This task will traverse all the dataobjects, and for each of them, will do a replace of every instance of the sitetree_link%20 and document_link%20 to the new notation. If dataobject is versioned, live and versioned records will also get converted.