SG: Option to hide the address in the initialization announcement

[willneedit]

Something like "&hide" to add into the Dial Computer's MRE URL to make it conceal its own address.

[willneedit]

I intend to retire the option line - perhaps I'll keep with the registration scheme and thus add a column to the database to flag addresses which are not supposed to be shown on init.

Thing is, the moment I publicize the list (maybe in Stargate Command) I'd need to have this flag accessible from other locations next to the DHD.