- edits for 1.3 migration notes
- edits for 1.3 migration notes

Change-Id: Id2065053088481df5a703c63bfc88799a9943a5e

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