supersede key on key-server

[Mike Acker]

some of us use more than one email address. with GPG it is simple to add 
a secondary ID to a key and this seems to work quite well.

when a change like this is made it is desirable to update the keyserver. 
what happens when you re-upload a key to the keyserver? I hate to think 
the keyserver gets loaded up with old junk keys no one want used anymore...

-- 
/MIKE