- move more active properties into their collections:

scene.active_keying_set --> scene.keying_sets.active
  ...same for active_uv_texture. active_vertex_color, active_keyconfig, 

- move mesh.add_uv_layer() and mesh.add_vertex_color() into their collections
  also have them return the newly created layer and dont set the layer active.

  uvtex = mesh.uv_layers.new(name)
  vcol = mesh.vertex_colors.new(name)

release/scripts/ui/space_image.py

@@ -316,7 +316,7 @@ class IMAGE_HT_header(bpy.types.Header):
             row.prop(toolsettings, "snap_element", text="", icon_only=True)
 
             # mesh = context.edit_object.data
-            # row.prop_search(mesh, "active_uv_layer", mesh, "uv_textures")
+            # row.prop_search_self(mesh, "active", "uv_textures")
 
         if ima:
             # layers