Skip export of objects flagged hide-from-render

[janEntikan]

Some objects can be purely referential or otherwise not intended to be included for conversion. This commit removes them from the scene right before export by disabling its renders visibility.

[rdb]

Would/should the collisions still be exported, or not?

[fireclawthefox]

There are at least two things that should be considered for collisions inclusion/exclusion.

1. If a designer want to render the model in Blender as reference he probably wouldn't want the collisions to be visible most of the times but still want them to be included in the exported model.
2. There might be a case where collision solids shouldn't be exported because they are only used for blender internal processes and would not be required in the resulting model. Without the possibility to exclude them that way, there currently wouldn't be another way.

[Moguri]

Closing due to inactivity.