tac_lite causes errors with new users (with patch)

Issue Summary

Hi,

I'm seeing errors on the first page seen by a new user. The errors are caused by tac_lite calling user_access() when the user hasn't been fully initialised. In my case I was seeing the problem on a Drupal install which used both tac_lite and webserver_auth.

I've done a trivial patch to the tac_lite_user() hook so that it only calls user_access() for ops that tac_lite cares about. As well as fixing my error I guess that this will be a (tiny) performance improvement.

Steve.