2D and 3D skeletons are now projected using the camera transformation so the
are placed correctly in the 3D world
Modified RenderSkeletonization to draw 2D and 3D skeletons
in diferent nodes, scene graph got a bit more complicated, but better
for code maintenance.
Added diagrams with the scene graph
Skeleton is now shown in little squares instead of points.
Code to merge 2D skeletons improved, but still does not work
Fixed errors on merging method, still not working as it should
Added method to get matrix T from camera.
Added new node to render merged skeleton.
Merged method now uses global coordinates to do the merging.
Changed method names in skeletonization 3D to be more explicit
Updated diagram
Merge method now uses at max 3 points for merging, still does not work
Fixed merging method. Now works but it is slow and it could give better
results.