Bug fixes

Fixes blank page issue raised in #183798 and introduces a couple of features from 6.x development work (user configurable exclusions and sortable tables).

See release notes at http://drupal.org/drupal-6.0-beta4

This is a minor, but critical bug fix.

Changes since DRUPAL-5--1-1:

• Fixed problem with hook_diff() when viewing non-webcam nodes.

Changes since DRUPAL-5--1-0:

Fixed menu item, to 'type' => MENU_NORMAL_ITEM. It should now appear.

Ok people, it's time to release the final 2.0.

* One more last-minute feature: An option "Don't assign roles to existing users" which comes in handy if you want to assign a "Temporary User" role to newly created temporary users but not to merely invited ones.
* Doing the code style maniac: Get rid of a NULL parameter which is now assumed by default.

That's it folks. Have fun, and hope for point releases instead of new release candidates :)