New 3d height map viewer

To display 2D image as height map:
![capture decran 2014-07-05 a 12 10 55](https://cloud.githubusercontent.com/assets/772865/3486505/6edb2144-043e-11e4-81c4-2c20f272a119.png)
![capture decran 2014-07-05 a 12 36 38](https://cloud.githubusercontent.com/assets/772865/3486506/728261cc-043e-11e4-8ca9-f9773ea5834e.png)