Remove the deprecated tag_item REST resource.
Remove deprecated Model_Item::get_position() function.
Revise Controller_G2::action_map() to no longer use deprecated "tag_name" route.
Controller_Rest_User - change 403 --> 404.
Add Controller_Rest_UserComments / UserItems resources.
Clean up some REST-related comments.
Make Controller_Rest_UserItems::put_members() / delete() more careful with order
Make GET /gallery3/rest return 200 if guest access is allowed (and 403 if not).
Merge pull request #407 from shadlaws/fixes_20130614

Fixes 20130614