- background job style cleanup.

- assert if material assignment is called with lib. (so the callers can be corrected).
- correct example docs

doc/python_api/examples/bpy.props.2.py

@@ -22,6 +22,6 @@ bpy.types.Material.my_settings = \
 # test the new settings work
 material = bpy.data.materials[0]
 
-material.my_settings.val_int = 5
-material.my_settings.val_float = 3.0
+material.my_settings.my_int = 5
+material.my_settings.my_float = 3.0
 material.my_settings.my_string = "Foo"