Remove Zend_Auth from libs dir as it is no longer used.

libs/Zend/Auth.php

libs/Zend/Auth/Adapter/DbTable.php

libs/Zend/Auth/Adapter/Digest.php

libs/Zend/Auth/Adapter/Exception.php

libs/Zend/Auth/Adapter/Http.php

libs/Zend/Auth/Adapter/Http/Resolver/Exception.php

libs/Zend/Auth/Adapter/Http/Resolver/File.php

libs/Zend/Auth/Adapter/Http/Resolver/Interface.php

libs/Zend/Auth/Adapter/InfoCard.php

libs/Zend/Auth/Adapter/Interface.php

libs/Zend/Auth/Adapter/Ldap.php

libs/Zend/Auth/Adapter/OpenId.php

libs/Zend/Auth/Exception.php

libs/Zend/Auth/Result.php

libs/Zend/Auth/Storage/Exception.php

libs/Zend/Auth/Storage/Interface.php

libs/Zend/Auth/Storage/NonPersistent.php

libs/Zend/Auth/Storage/Session.php

tests/PHPUnit/Core/AccessTest.php