Blender Git Loki

Fix relationship lines in draw manager [*]

This fix doesn't really fix the situaion now because at the moment we
only flush the evaluated flags at DEG_OBJECT_ITER time, which is silly.

But it's all we can do until we have CoW.

So the parent visibility flag is not flushed. And even if we flushed its
visibility flag, we would need to rely on having the parent flag flushed
before we get to the object in question.

Anyways, take this commit as a future fix for when depsgraph comes to
rescue all our souls.