Superseding properties are created as well as those which they supersede #152
Description
When using the flag allProperties, the properties which supersede other properties are also generated, resulting in the following class with errors regarding duplicate properties:
For example, in CreativeWork, award supersedes awards.
/**
* @var string|null an award won by or for this item
*
* @ORM\Column(type="text", nullable=true)
* @ApiProperty(iri="http://schema.org/award")
*/
private $award;
/**
* @var string|null awards won by or for this item
*
* @ORM\Column(type="text", nullable=true)
*/
protected $award;