Allow for configurable legal screen

[bigkevmcd]

A configurable proprietary information statement and legal warning (i.e. message stating that only authorized users may access the system) shall be displayed on the initial entry screen before any logical access is allowed.

I suspect we want to check for the presence of a cookie, if not present, we display the information statement, which perhaps comes from a ConfigMap key.

We set the cookie to indicate that we've shown the user it (or perhaps when they acknowledge that they've seen it).