Dups created for multiple calls of createdb

Mike, 

I noticed the bug you submitted: 841895 for the dupes in the user table.  But
isn't the problem grander than just svc-authorization-persist?  Any table that
doesn't have one of their "supposed to be unique" column as the primary key,
dupes get created from multiple calls to createdb....

This is pretty destructive.  If its not fixed in 2.1, what about changing it to
at least take no action if the table already exists?

-Nate