Permissions table for restricting roles that a user can assign

Added a permissions table that end users can configure in order to restrict what roles a group member can assign.

The configuration of the permissions table is described in OGUR Settings documentation here: http://drupal.org/node/163567

Documentation on the permissions that are now created by OGUR (as of 6.x) is here: http://drupal.org/node/397954

The permission to give a user who you want to have "restricted" access to configure roles is configure restricted member roles (as opposed to "configure member roles").

So note that:

configure member roles allows a user to assign any group role.

configure restricted member roles allows a user to only assign roles for which he has permission according to your configuration of the permissions table.

This now gives you more control over what roles can be assigned by users in your groups.