Show/Hide only allowed on Objects, shown on Armature/Bone Panel UI

[tngreene]

It appears that Show/Hide animations only work for Meshes. Maybe I made my test case too quickly, but also, this was brought to my attention by a person who said their converter project's show/hide animations weren't exporting from the Bone they were on.

The OBJ spec does not say anything about ANIM_show must be directly before a TRIS call. I think this is a bug, otherwise, it should be hidden from the UI with warnings and such. Pretty sure this is just a bug.