ud-info: Add "retire developer" option that sets accountStatus properly to

either retiring, retired, memorial or active.  Active is for all currently
active developers, memorial is for those who have passed away and whose
accounts will never be reused, retiring is a developer who is retired but still
receives mail at their @debian.org address.  After a few months they should
move on to retired, with their mail also disabled.  accountStatus is just a
freeform text, but these 4 options should be the only ones that exist.