3D View: add initial view.shading and view.overlay in RNA.

These are mostly empty still, many properties need to be renamed and moved there.

tests/python/bl_mesh_modifiers.py

@@ -38,12 +38,12 @@ USE_QUICK_RENDER = False
 
 def render_gl(context, filepath, shade):
 
-    def ctx_viewport_shade(context, shade):
+    def ctx_shading_type(context, shade):
         for area in context.window.screen.areas:
             if area.type == 'VIEW_3D':
                 space = area.spaces.active
                 # rv3d = space.region_3d
-                space.viewport_shade = shade
+                space.shading.type = shade
 
     import bpy
     scene = context.scene
@@ -59,7 +59,7 @@ def render_gl(context, filepath, shade):
     render.resolution_x = 512
     render.resolution_y = 512
 
-    ctx_viewport_shade(context, shade)
+    ctx_shading_type(context, shade)
 
     #~ # stop to inspect!
     #~ if filepath == "test_cube_shell_solidify_subsurf_wp_wire":