Description:
------------
According to the manual, the PDO method getAvailableDrivers() is static:

"This function returns all currently available PDO drivers which can be used in DSN  parameter of PDO->__construct(). This is a static method.",
http://de.php.net/manual/en/function.PDO-getAvailableDrivers.php

That's not true. You can invoke it using static and non-static syntax. I'd call it a feature not a bug. In any case it should be documented.

Reproduce code:
---------------

nixnutz@ulflinux:~/php53> sapi/cli/php -r '$pdo=new PDO("sqlite:/tmp/foo.db"); var_dump($pdo->getAvailableDrivers()); var_dump(PDO::getAvailableDrivers());'
array(4) {
  [0]=>
  string(7) "sqlite2"
  [1]=>
  string(6) "sqlite"
  [2]=>
  string(5) "pgsql"
  [3]=>
  string(5) "mysql"
}
array(4) {
  [0]=>
  string(7) "sqlite2"
  [1]=>
  string(6) "sqlite"
  [2]=>
  string(5) "pgsql"
  [3]=>
  string(5) "mysql"
}



Expected result:
----------------
I'm fine with the implementation, no change. But decide on the question if its a feature or a bug.