[sensors] Update the depth camera

Decode the depth information comming from the patched Blender.
Data should be stored as a single unsigned int of 4 bytes instead of the usual
RGBA of the VideoTexture module.
The sensor will convert this value back to a float and do the conversions to
get a 3D point for each pixel.

This requires a patch to Blender, which will be added in the next commit
Patch for Blender to be able to export z-buffer

This is a temporary solution, while the patch is applied to the Blender
distributions
[testing] Relax a bit the test on video_camera
Informations => information (never 's' in english)
[testing] Adjust the position of pose sensor in segway test
[actuators] update rotorcraft actuators to use add_data/property
[examples] add example scene for dynamic quadrotor
[builder] fix frequency when trying to explicitly set it to the same as the fps
[hla] improve logging
[hla] force the server address to localhost in hla tutorial
[hla] tutorial for hybrid simulation using Python
[hla] Rename hybrid tutorial files
[hla] Hybrid simulation tutorial in doc
[doc] Fix the blender requierement in installation documentation
[doc] Prepare documentation for 0.6
[doc] Prepare release notes for version 0.6
[doc] Mention Sylvestre in the authors list
[doc] Mention several publication on Morse
[doc] Kill another reference to version 0.5
[doc] Added results of the first MORSE user survey.