Cycles-Bake: remove assert and comment cleanup
Cycles-Bake: normal swizzle, and OBJECT and WORLD normal spaces

The user can now decide between the normal_space (OBJECT, WORLD)
The user can now decide on the swizzle (+X,+Y,+Z):
 * normal_r, normal_g, normal_b

+ barebones code for TANGENT normal space
  Though this is not working, thus it's disabled in operator enum.