Simulated Camera

[vincenzosu]

I have implemented a simple way to show the camera POV of the robot but it's mostly hardcoded.
The following problems must be solved:

• set the position of the camera in the .xml file according to the real camera
• define the camera according to the real one used by the robot (check the comment inside the SimulationViewport.cpp file)
• select the possibility of visualizing the camera of a specific robot through the menu
• move the secondary window as you wish