[Command] Added LockHelper

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes https://github.com/symfony/symfony/pull/10475
| Applies to    | Symfony version 2.6+
| Fixed tickets | -
I would reverse the order of this paragraph this way:

```
The resource is automatically released by PHP at the end of the script. In addition,
you can invoke the :method:`Symfony\\Component\\Filesystem\\LockHandler::release` method
to release the lock explicitly. Once it's released, any other process can lock the resource.
```