When using a PDOConnection and the Portability wrapper, the default value \PDO::CASE_NATURAL int(0) and PHP constant CASE_LOWER int(0) got mixed up.

Fixed a few cases of where MysqliStatement::execute() did not throw a exception if a error had a occured.

Hopefully final fixes. Added phpdoc @inheritdoc where it were missing. Added MysqlConnection::getWrappedResourceHandle(). MysqliStatement::fetchAll() now decide fetch style if none is set, instead of letting fetch() do it on every call.

This enables a more natural way of interacting with result sets,
and re-introduces in Doctrine DBAL a feature that has been available
in PDO from the begining.

DDC-1266 - Fixed bug where one sequence is dropped multiple times and extended that logic to tables and constraints

DDC-217 - Refactor result caching to use a value object for all the important information which simplifies the code considerably and makes caching more powerful.

DDC-217 - Refactor result cache again to be much simpler, previous approach was too complicated and something like this needs longer testing. Now only caching the full result.