CSG Support for Godot!

-Missing Icons
-Missing freezing option (for baking light and faster load)
-Missing a way to export from Godot (GLTF2?)
-Probably buggy (may freeze editor, can be worked around easily, but let me know if this happens so it's easier to catch bugs)
Happy testing!

modules/csg/config.py

@@ -0,0 +1,5 @@
+def can_build(platform):
+    return True
+
+def configure(env):
+    pass