added option for 'on duplicate key update' clause to Model.

Merge branch 'master' into non-mvc

avoid php 5.4 warning from Postgres adapter

Merge branch 'master' into non-mvc

return type for Model::retrieveByColumn, no more limit in retrieveByPK

if (' '==0) echo 'insane'; // (closes #3732)

shorter text in Query methods doSelect, doDelete, and doCount

support for multiple database connections. connections should now be …

…saved in DBManager using the database name instead of a random label such as "main"

change case of attribute values to be compliant

support for multiple database connections. connections should now be …

…saved in DBManager using the database name instead of a random label such as "main"