#100 New OBJ Exporter features

[MaxG]

I think that the Wings3D OBJ Exporter need of some
implementations for a greater compatibility with the
existing OBJ importers.
Please consider integrating "ke" flag also for the emission
property with rgb color parameters like "ka", "kd" etc.
(no coefficient).

In the EXPORT panel:

• Triangulate: ON/OFF. The triangulation is very
  important for a greater compatibility with many many 3D
  software. The triangulation in the exporting session is a
  useful non-destructive operation ;)

• Write VN: ON/OFF. Vertex Normal writing option.

• Write VT: ON/OFF. Vertex Texture writing option.

• One Group: Absolute/Per Material/Per Object/None.
  This is a list option instead of original "One Group per
  material". With "Absolute" Wings write only one group up
  to objects and materials. With "Per Material" Wings write
  a group every material. With "Per Object" Wings write a
  group every object. With "None" Wings don't write any
  group.

• d/tr command. List option. With this option Wings
  write the diffusion pigment command with "tr" instead
  of "d" and vice-versa.

• map_d/map_tr command. List option. With this option
  Wings write the trasparency map command
  with "map_tr" instead of "map_d" and vice-versa.

• refl/map_refl command. List option. With this option
  Wings write the reflection map command with "map_refl"
  instead of "refl" and vice-versa.

• Custom flags. Textbox. With this option Wings custom
  commands down to first comments.

In the MATERIAL panel:

• ILLUM Mode: 0/1/2/3/4. Write the rendering
  illumination mode.

• map_ka: filename option for the ambient texture.

• map_kd: filename option for the diffuse texture.

• map_ks: filename option for the specular texture.

• map_ke: filename option for the emission texture.

• map_ns: filename option for the shininess texture.

• map_d/map_tr: filename option for the opacity texture.

• refl/map_refl: filename option for the reflection texture.

Best regards,

Max