A global admin option allows site administrators to disable the
information entirely, though it is enabled by default for all new and
existing sites.

Users can opt not to show the information, and an account setting is
present if they wish to have it shown again. The information is shown
between the home page text set by the admin, and the user's dashboard
view.

Signed-off-by: Evan Goldenberg <evang@catalyst.net.nz>