Decoupling x-ray and limit selection to visible

[Hologram]

For the latest update see:

X-Ray selection experiments build

Been busy with some other things but also with adding features to this build that have been on my list for a while. First one is ignoring backfaces, spent a while trying to get that working but couldn’t figure out the important part where you get accurate information about face normal vs the viewport. I was trying to just subtract one from the other, but then I got some seriously appreciated help with that from @Chris_Blackbourn. Need to add it to xray which should be easy, then also do edges, a…

That’s the status as of now. No official Blender devs involved still apart from some feedback from @JulienKaspar