there are three options:
0) Hide the email address from everyone (except the teacher of their course)
1) Allow everyone to see the email address, all the time.
2) Allow only participants in the same course to see the email address
Note, new field maildisplay in 'user'
servers that have register_globals turned off (this is the
default setting on newer version of PHP).
In fact it's partly a hack that globalises all GET, POST, FILES
AND COOKIE variables. Unfortunately though the SESSION and
USER global session variables are only available as $_SESSION["USER"]
and $_SESSION["SESSION"], which is cumbersome to use.
So, for every request I now make a copy of these two session variables
into $USER and $SESSION. Whenever I update them thoughout Moodle I
now have to call save_session("USER") which copies them back to the
session variable. This seems to be working well now.
Because I'm using $_SESSION etc now this will raise
the required minimum version of PHP to 4.1.0
rely on the administrator to tell us which is installed because PHP
is not reliable (eg GD 2.* functions are available in 4.0.6 and later
EVEN WHEN gd 2 is not present ... sigh).
So, new config variable $CFG->gdversion
