Description:
------------
By default D-Bus method call is limited by 25 seconds.
I believe, that it would be useful to have an ability to set and get timeout parameter for D-Bus calls.

Test script:
---------------
$dbus = new Dbus(Dbus::BUS_SYSTEM);

// If this method would exist
if (method_exists($dbus, 'setTimeout')) {
   // This is the way to set infinite timeout.
   $dbus->setTimeout(Dbus::TIMEOUT_INFINITE);
}

$proxy = $dbus->createProxy('net.php.bugs.service', '/obj', 'iface');

$timeout = $dbus->getTimeout();
echo 'Max call time is '
   .($timeout == Dbus::TIMEOUT_INFINITE? 'infinite': "$timeout seconds");

$proxy->someLongMethod();


Expected result:
----------------
Max call time is infinite

Actual result:
--------------
As a result PHP-developers, who use Dbus, will be able to set required time for Dbus methods call. That is specially useful, when one deals with long net or database interactions.