added supportsReleaseSavepoints(), disabled releasing for Oracle and DB2 (already disabled for MSSQL

added supportsReleaseSavepoints(), disabled releasing for Oracle and DB2 (already disabled for MSSQL

Added registerDoctrineMappingType() and getDoctrineMappingType() methods, converted DB2 platform and added some tests, made all platforms work for now

Support Sqlite

Migrated MySQL to Doctrine Type Map

Fixed nasty bug in testcase

Migrated Postgres to support Doctrine Mapping Types

Refactored Oracle Platform to support Doctrine Mapping Types

Refactored DB2 support for Doctrine Mapping Types a little bit

Fixed pecl/ibm_db2 Driver and Connection to run smoothly against the complete test-suite (depending on a c-patch to the extension though)

DDC-496 Finished first versions of platform and schema manager for DB2, DDC-528 Added support for PDO_IBM driver, passing all but 3 tests that are related to CLOB fields