Setting up another data czar

@shnayder  @mhoeber @WatsonEmily @stroilova : now that it is possible to add a second data czar, best practice remains to have just one at a site, but to add a second data czar rather than have them share a single passphrase (we just don't want all partners to add lots of people all over)
nit: I'd remove "strongly". There are good reasons to have a backup.