Drop base Annotation ancestor

[Majkl578]

This PR drops the Doctrine\Annotations\Annotation base annotation class.

It was an inheritance abuse that basically existed only for convenience:

• to implicitly define default $value property,
• to behave like stdClass and dynamically set undefined properties (without validation).

[Ocramius]

I don't think the base class should be removed, as it makes the BC break muvh bigger than needed: a deprecation would probably be better

[Majkl578]

I was rather thinking about deprecating it in 1.7 and going with less burdens in 2.0. Mostly because this class is rarely used out there. But I may be wrong, GitHub search is not very helpful in finding usages.

[alcaeus]

Deprecating it in 1.7 would be the first step before dropping it from 2.0. We can then see what people say and either decide to revert the deprecation or go along with the removal.

Sneak edit:

GitHub search is not very helpful in finding usages

I checked our application at work and found the following packages extending the annotation class:

• FOSRestBundle
• Gedmo Doctrine Extensions
• Doctrine MongoDB ODM (we already discussed this and will most likely drop it in 2.0)

[Ocramius]

LGTM. The question that remains before merge is if we should stop plans for 1.7.0 and make master 2.0.0 instead. I'd delete the milestone and re-assign everything to 2.0.0 then.

[alcaeus]

Master is 2.0.x-dev already.

[Ocramius]

Right, I'm moving all of 1.7.0 stuff into 2.0.0 then.

[alcaeus]

Please don’t - 1.7 will be necessary to deprecate features that will be dropped in 2.0 as per SemVer.

[Ocramius]

As per discussion with @alcaeus and @Majkl578, master is already 2.0.0, so this can be merged nao.