Add forward declarations for dereference(device_ptr) to normal_iterator.h to WAR circular #inclusion problems.
Add forward declarations for dereference(device_ptr) to normal_iterator.h to WAR circular #inclusion problems.

--HG--
extra : convert_revision : svn%3A83215879-3e5a-4751-8c9d-778f44bb06a5/trunk%40352

jbrownbridge/thrust,jbrownbridge/thrust,jbrownbridge/thrust,jbrownbridge/thrust