populating FKs from _bz_schema at the end of checksetup, store REFERENCES in _bz_real_schema with a special "created => 0" key that tells us that we still need to create the FK. r=mkanat, a=mkanat (module owner) git-svn-id: svn://10.0.0.236/trunk@260775 18797224-902f-48f8-a5cc-f745e15eee43