Arctan & Port

Hacked together a bit of Python to calculate an arctan table. Requires a bit of code to avoid using more than +/-45 degrees. The plan is that Alan and I will test this code in Python before moving it to C++. This is for the bearing calculation. We wouldn't have needed the actual angle for steering alone but we also need to rotate the plan view.

Also moved revised 3D calculations from the Red Extract test app to the robot code and got it compiling. Really need to tidy up the code in that area at some point - it's a real mess, but that prettification can wait till later when the robot does something. Currently I'm in the process of adding the camera angle and x-offset as parameters in the EEPROM so they can be modified without recompilation.