[WIP] Compute resolution and depth map (moved)

Adding files (cloud.cpp / cloud.h + image.h) to :

1. automatically compute angular resolution (vertical/horizontal) of an unknown pointcloud
2. build a depth map from the pointcloud using previous features
3. extract image neighborhood
4. compute normals using this neighborhood
5. compute a normals image. All steps are performed tackling the real time issues. @nicolas.cadart