Merge pull request #660 from JimBrown/1.4.6

Change use of dirname() in register_user.php
don't require pass by reference
use __constructor()
PersistentObject method not really a constructor

This violation of naming convention did cause some confusion, so we
rename the function to prevent future misunderstanding.
do not pre-load deprecated functions script for internal deprecations

These will give missing class errors then, but what do you want if the
deprecated functions plugin is not enabled.
supress admin toolbox when user cannot do anything

Also ties deprecated and rewriteTokens tabs to ADMIN_RIGHTS