Fix #1462 Add new method for Phalcon\Mvc\Dispatcher

[dreamsxin]

See #1462

$this->dispatcher->getPreviousControllerName();
$this->dispatcher->getPreviousActionName();

[phalcon]

I think this is something a developer could implement using plugins, this would add more overhead to every request in every application, doesn't it?

[dreamsxin]

Only call forward will set these two values and very useful, I had wanted to establish a list of saved repeatedly foward

[phalcon]

Thanks