- 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/io/export_3ds.py

@@ -567,7 +567,7 @@ def extract_triangles(mesh):
         f_v = face.vertices
 # 		f_v = face.v
 
-        uf = mesh.active_uv_texture.data[i] if do_uv else None
+        uf = mesh.uv_textures.active.data[i] if do_uv else None
 
         if do_uv:
             f_uv = uf.uv
@@ -998,7 +998,7 @@ def write(filename, context):
                     if not mat_ls:
                         mat = mat_name = None
 
-                    for f, uf in zip(data.faces, data.active_uv_texture.data):
+                    for f, uf in zip(data.faces, data.uv_textures.active.data):
                         if mat_ls:
                             mat_index = f.material_index
 # 							mat_index = f.mat