DBAL-33 - Added flexible DateTime type that can be used as replacement when variable date/time parts are returned from the database, for example with PostgreSQL TIMESTAMP(n) and TIME(n) types

DBAL-26 - Fix nasty bug with null values in Date, DateTime, DateTimeTz and Time fields introduced with the DBAL-22 fix

DBAL-22 - Throw ConversionException if DateTime, Time, Date, DateTimeTz, Array or Object conversions from the Database to PHP fail

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