Form element annotation builder: ToMany and ToOne support

[Ocramius]

Adds *ToMany and *ToOne support to the DoctrineORMModule\Form\Annotation\ElementAnnotationsListener

Cleaned up version of #191

[spiffyjr]

Oh, you did the CS fixes for me, eh?

<3

[Ocramius]

@spiffyjr yes, but I'm delaying it as you can see from the modified UPGRADE.md. (It was easier to pull and fix than to comment on each CS problem :) )

[spiffyjr]

Works for me, thanks.

[internalsystemerror]

Is the ElementAnnotationsListener::attach() method not missing:

$this->listeners[] = $events->attach('configureElement', array($this, 'handleToOneAnnotation'));

Also, would it be possible not to override the $elementSpec['spec']['options'] array and instead to extend it? That way, its possible to set the property in the annotations instead of forcing the use of __toString().

[BrunoSpy]

Is there some doc somewhere which describe how to use this new feature ?