This will standardize the way that Mahara sanitizes these personal
details.

PHPMailer is no longer necessary since in PHP 5.2, it's just a
call to filter_var().

Change-Id: I151fe4f91c9731cfa24b5a6e9d0cebeabfcd1a77
Signed-off-by: Francois Marier <francois@catalyst.net.nz>