Log Message:
Changes 1.2.0:
- A major revision of memory management to limit memory usage by slon
  daemons.
- Log switching: periodically
- pg_listener is now used dramatically less than it used to be, which
  diminishes the number of dead tuples you will find in this table.
- DDL scripts are broken into individual statements
- Slony-I tables are now marked "WITHOUT OIDS" so that they do not
  consume OIDS.
- When possible (based on log switching functionality), partial
  indexes on sl_log_1 and sl_log_2 are created on a per-origin-node
  basis.
- More...