Migration does not quote identifiers when checking migration version

I happen to be using Symfony 1.4.14-DEV (r33007) and am trying to setup migrations with Oracle, which is using Doctrine_Core::ATTR_QUOTE_IDENTIFIER. This issue is in core Doctrine.

To reproduce:

1. Make a change to your schema.yml
2. Create the migrations diff by executing php symfony doctrine:generate-migrations-diff
3. New file have been created at ./lib/migration/doctrine/*_version1.php
4. Try to migrate using command php symfony doctrine:migrate
5. Results in error:

ORA-00942: table or view does not exist : SELECT version FROM migration_version. Failing Query: "SELECT version FROM migration_version"

Cause: The current connection is using quoted identifiers, so the query used to create the migration_version table when migrations are first instantiated was properly created as "migration_version" (notice quotes). But the raw SQL query used in Doctrine_Migration::getCurrentVersion() is not quoting the table or column identifiers, so Oracle can't find the table.

There are several places in Doctrine_Migration where the table and column identifiers are not quoted, thus breaking migrations when using a database with strict rules on the case of identifiers.

Even though I'm developing against Oracle, this also likely affects other drivers.