* Move the show/hide advanced button a bit down the page.
* Improve save button caption when creating a role.
* Don't show defaults on the basic define roles screen.
* Explain the background shading on the advanced roels screen.
* Fix the problem with the risks link to Moodle docs.
* Help icon by the permissions column heading.
* Tables with rotated <th>s, make them vertical-align: bottom.
* Rename explain.php and explainhascapability.php to check.php and explain.php
* Tool tips on the number headers in the explain table.
* Explain table - role names were missing.
* Allow link_to_popup_window to work with full URLs.
I have collected code that used to be in lib/adminlib.php, lib/accesslib.php and user/selector/lib.php into a new admin/roles/lib.php file.
And I added standard GPL and Moodle comments to all the files in admin/roles.
This implements the page showing the table. It is not yet integrated into the tab bar. To try this, go to an Assign roles page (one with URL .../admin/roles/assign.php?contextid=...) and change the 'assign' to 'explain'.
Petr Skoda