Fix up verbiage on what privs that project_root and group_root have

wrt subgroups. Also noted that group created is no longer in the group
by default.

www/groups.html

 <!--
    EMULAB-COPYRIGHT
-   Copyright (c) 2000-2002 University of Utah and the Flux Group.
+   Copyright (c) 2000-2003 University of Utah and the Flux Group.
    All rights reserved.
   -->
 <center>
@@ -34,15 +34,20 @@ group, etc.).
 </p>
 
 <p>
-As project leader, you may create and destroy subgroups, and add or
-remove project members from your groups. You are automatically a
-member of new groups you create; even though you are not the
-designated leader of the group, you still retain all of the same
-permissions that you have as project leader, within the group. This
-means that you can terminate experiments that have been created within
-the group, and edit the personal information for group members. To
-create a group, simply go to the Project Information link at your
-left, and look for the "Create New Group" link, or go to the <a
+As project leader (or a group_root in the project), you may create and
+destroy subgroups, and add or remove project members from those
+groups. You can make yourself the leader of a subgroup, but more
+typically you would designate someone else to lead a subgroup. While
+you are not automatically a member of new groups you create, you may
+add yourself after the group is created using the group edit page.
+However, you do not have to put yourself into the subgroup; you have
+all the same privledges in the subgroup. The main difference is that
+your home directory will not be available on nodes belonging to
+experiments created in subgroups (see below). This means that you can
+terminate experiments that have been created within the group, and
+edit the personal information for group members. To create a group,
+simply go to the Project Information link at your left, and look for
+the "Create New Group" link, or go to the <a
 href=https://www.emulab.net/newgroup_form.php3>Create New Group</a>
 page directly.  Once you have created a group, you can edit the
 members of the group by clicking on the "Edit" option in the group