Rotation `roll` should perhaps be inverted, like `pitch` is

[Skaruts]

It seems entities are being imported with incorrect roll from angles. I was noticing when I "rolled" entities one way in TB, they would appear rolled the opposite way in Godot. I changed this code to use -roll and it fixed it. So far so good.

https://github.com/codecat/godot-tbloader/blob/84a891f6499439c079833b8cf1c8335e8fec0c29/src/builder.cpp#L328-L332

I haven't tested this with mangle, since I have no use for it.