[fixed] Exporting models with holes doesn't work.

[Nova]

Exporting models with holes in 2.1.5 doesn't work at all. Every time I import these the holes will be filled back in. It seems as if the holes gets treated as hidden faces instead of actual holes.

I tried with .3ds, .obj and .dae and all exhibit the same problem. If I export with 2.1.5 holes are not exported. If I export with 2.0.4 everything works as expected. To reproduce:

1) Make Cube
2) Make any face a hole
3) Export
4) Import

For me, this is a huge problem as I use holes to lower the tri count of many of my models. With the holes not getting exported correctly, I simply can't use the models because of flickering, non uv'd faces as well as the increased tri count.