[Command] New command to help newbies to setup project permissions (acl)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | no
| License       | MIT
| Doc PR        | no

Implementing "Setting up Permissions" instruction from docs http://symfony.com/doc/master/book/installation.html#configuration-and-setup
Can you add the parameters to the exception for debugging purposes? You also do `getContainer()`, you can put it in $container so you only have to call the getter once, also makes it slightly more readable.