Added EventSubscriberInterface marker interface to support autoconfiguration

[lyrixx]

fixes #674

By implementing Doctrine\Bundle\DoctrineBundle\EventSubscriber\EventSubscriberInterface, your Doctrine ORM Subscribers will be automatically configured

[ostrolucky]

This is solution for #821 right? But interface proposed in this PR looks nothing like proposals in issue.

[lyrixx]

Nope, it's for #674 as stated in the PR description.

[alcaeus]

LGTM. I've moved this to master (2.1.x-dev) as SemVer requires the new interface to be introduced in a new minor release.

[alcaeus]

Thanks @lyrixx! 🎉

[rvanlaak]

Brilliant in its simplicity! 👏

Would it be possible to on userland let DI alias the old interface for the new one, so without making code changes to PHP this autowiring could get used (read: tested) on our application?

[lyrixx]

@rvanlaak thanks.

If you are using only the ORM (and not the ORM) (see explaination here you can do that:

services:
    _instanceof:
        Doctrine\Common\EventSubscriber:
            tags: [ doctrine.event_subscriber ]

[rvanlaak]

Had that one in mind, which probably is sufficient. Was more thinking of something conceptual like:

Doctrine\Common\EventSubscriber:
    alias: Doctrine\Bundle\DoctrineBundle\EventSubscriber\EventSubscriberInterface 

This in order to gain advantage of all functionality the doctrine bundle in the possible future would add via DI (e.g. tags, compiler passes) based on EventSubscriberInterface.