Remove old FixVersioned

We should be ok doing this yes? and why is Git wanting to replace whole file all the time?

see line: 207:
return FixVersioned::get_version('ProductVariation', $this->ProductVariationID, $this->ProductVariationVersion);

should just be 
return Versioned::get_version('ProductVariation', $this->ProductVariationID, $this->ProductVariationVersion);

maybe