[core] Provide a way to call the mathutils.Matrix ctor without argument
[doc] Improve documentation of camera related sensors

- move image and intrinsic matrix from camera to video_camera
- fix the documentation of generic camera
- fix some copy-paste issue on depth_camera
- document data in {video, depth}_camera

XXX depth_camera is not connected to build, because it can be imported
(zbufferto3d lacks symbol PyMemoryView_FromMemory with python 3.2)
[sensor] Rework pose sensor

- Simplify it
- use add_data to create and document entry for local_data
[testing] Restore a test in waypoint commented by error
[testing] PR2 does not exist anymore, use BasePR2

Tests are still broken through ...
[sensor] Rewrite semantic_camera logic + improve documentation
[middleware] Adapt socket datastream to new class model
[middleware] s/initalize/initialize/g

Hi Pierrick :D Good typo :D
[sensor] kinect