fix usage of PDO::PGSQL_ATTR_DISABLE_PREPARES for pdo_pgsql extension setups not built from PHP core

fixes #2249

Features and changes:
* jsonb can be used with: options={"jsonb"=true}
* OVER is no longer reserved
* LATERAL is now reserved

Fixes #402 (https://github.com/doctrine/DoctrineBundle/issues/402) by connecting by default to 'template1' instead of the database with the same name as the user (Postgre default in case of no dbname).

Add support in fetch for type PDO::FETCH_OBJ

As seen here => http://technet.microsoft.com/en-us/library/cc626307(v=sql.105).aspx

The PDO connection allow the instantiation of the connection even if the dbname
parameter isn't present. This change is there to make sure both behave the same way.