* mothermapper has a slow computatinal model. For great DB, it's slow.
  Optimizations should be nice (see postgres autodoc).

* mothermapper new option -M: write the declaration of  Mother classes
  for each table on the DB, using MotherManager automatically when a 
  table has children or relations. Perhaps this is not a good idea

* Let use MoFilter at the upper level

* adding other database is now easy
