Display 2D and 3D image primitive in Display3D (now only in DisplayViewer)

Adding  2D and 3D image primitives in Display3D.
The display follows the classic display with also DrawWithDisplay3DModifier :

Viewer3D view;
view << image2D;
viewer <<  DGtal::UpdateImagePosition(1, DGtal::Display3D::xDirection, 50.0, 0.0, 0.0);
viewer << DGtal::UpdateImageData<Image2D>(0, sliceImageZ, 0, 0, 10);

(with image2D and image3D can be a DGtal::ImageContainerBySTLVector)
It contains also examples and doc update (and contains a merge  of the branch of PR #595)
To test you can also just test on an already merged:
https://github.com/kerautret/DGtal/tree/masterForVisu
A simple slice tools is also given on a special branch: (with few around 200 lines of code)
https://github.com/kerautret/DGtalTools/tree/masterForVisu
![capture decran 2013-05-15 a 01 40 14](https://f.cloud.github.com/assets/772865/504586/b78189d4-bcef-11e2-9fad-ad864066e72e.png)
and different mode:
![capture decran 2013-05-15 a 01 43 18](https://f.cloud.github.com/assets/772865/504595/192d9010-bcf0-11e2-99af-75bb0d2dc8f5.png)