Adding PDO as hard dependency as per discussion in #808

Close #713
DBAL-1030

Added missing filtering of table name assets in DB2SchemaManager

Close #2704

#2704 - Removed hacky handling of error handler restore operations - restoring twice in the test instead

MySQL: Fix primary key alteration when adding new columns

Fix docs for Doctrine\DBAL\Id\TableGenerator

primary key on MySQL platform.

MySqlPlatform: Fix default isolation level

Default isolation level on mysql is REPEATABLE READ

https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_tx_isolation

[Oracle] getListTableColumnsSQL returns columns ordered by position instead of by name.

Add missing SSL parameters to pdo_pgsql driver

Fix copy+paste error in testListTableColumns

Slash before '_' in postgresql like condition with 'pg_' prefix