Add @Flow\Scope("singleton") annotation where necessary.
Merge pull request #26 from martin-helmich/bug-add-singleton-annotation

Repositories need to be of @scope("singleton")
Merge remote-tracking branch 'upstream/master' into feature-doctrine-fullmigration

* upstream/master:
  Add @Flow\Scope("singleton") annotation where necessary.
Track if classes are abstract.
Fix brainbug with wrong column names.
Handle many-to-many relations.
Remove @Flow\Entity for non-persisted entities.
Don't use @Flow\ValueObject annotations.

Just handle everything as entity, this is not worth the hassle.
Only add Doctrine annotations when TCA was found.