Removed adapter docs since it is not working.

manual/docs/en/connection-management/opening-a-new-connection.txt

@@ -11,23 +11,3 @@ try {
     echo 'Connection failed: ' . $e->getMessage();
 }
 </code>
-
-If your database extension isn't supported by PDO you can use special {{Doctrine_Adapter}} class (if available). The following example uses db2 adapter:
-
-<code type="php">
-$dsn = 'db2:dbname=testdb;host=127.0.0.1';
-$user = 'dbuser';
-$password = 'dbpass';
-
-try {
-    $dbh = Doctrine_Adapter::connect($dsn, $user, $password);
-} catch (PDOException $e) {
-    echo 'Connection failed: ' . $e->getMessage();
-}
-</code>
-
-The next step is opening a new {{Doctrine_Connection}}.
-
-<code type="php">
-$conn = Doctrine_Manager::connection($dbh);
-</code>