Add a selection dialog from which the user can disable the chatzilla,
deflenus, mail, psm and talkback components. This is based on the
recent work on the www/linux-netscape6 port. When psm is omitted,
Mozilla still shows the Privacy and Security menus, and complains
about not being able to load libpipboot.so. When talkback is
omitted, Mozilla makes noise about the missing libqfaservices.so.