- categorize these two with_polymorphic subsections under with_polymorphic
- categorize these two with_polymorphic subsections under with_polymorphic

Change-Id: I8bd49ac241df4b8645c8f78938d6f8122952d75a

graingert/sqlalchemy,j5int/sqlalchemy,j5int/sqlalchemy,wujuguang/sqlalchemy,sqlalchemy/sqlalchemy,graingert/sqlalchemy,monetate/sqlalchemy,zzzeek/sqlalchemy,wujuguang/sqlalchemy,monetate/sqlalchemy