DBAL-22 - Fix DateTime with Timezone handling in Postgres and Oracle by introducing new type DateTimeTz and have SchemaManagers of both platforms detect this type. Added general conversion testcase which made some bugs in Oracle Date Handling and $stmt->fetchColumn() appear

[2.0] DDC-294 - Added "postConnect" event in Doctrine\DBAL\Connection and refactored TestUtil to allow configuration of DBAL EventManager Subscribers by the use of PHPunit Xml configuration.