Remove bboxes clipping

[rafis]

fixes #882

[hgaiser]

How does this fix #882 ? The error comes from loading the annotations, but you removed the clipping from the output of the network?

[rafis]

Yea, it is not optimal solution. Some annotation tools does not support annotating bboxes outside of image shape. But I have tested this code and it works. Model successfully predicts those bboxes as like object being occluded by another object.

[hgaiser]

Ah I see now that you also removed the check from the generator. I'm not a big fan of this change. In my opinion the annotations should be inside the image and so should the predictions.