Changes for 4.6

Couple changes for 4.6. First this is now a private module - _node_access_join_sql() so that needed to be changed.

Also, if you have the taxonomy module but haven't set your mail_archive to be part of a taxonomy then there should be an option to just print out all of the mail_archives in a formatted structure. Decided to just set up a taxonomy, but added some changes that are based on the assumption that taxonomies are being used as anticipated.

Mike