Small change to lua test script.
Added velocity control classes for 2d dynamics engine. In this way, it is easier to make robots whose movement is controller in speed. Added also a specialized differential steering control designed for 2-wheeled robots.
Ignored a class in Doxygen.
Now error messages are printed before destroying, to prevent further error messages from blowing everything up.
Changed "Position" in proximity sensor equipped entity into "Offset"
Minor change
Minor change
Small fix to font for multiline comments in lua editor. Now it's italic as it should.
Changed name of CLuaUtility::CallFunction into CLuaUtility::CallLuaFunction()
Fixed memory leak in CLuaController::Destroy()
Removed empty lua test script
Now new lua scripts are filled with a template.
Restored gripping functionality.

1. fixed the gripper equipped entity;
2. added a default generic gripper actuator;
3. fixed the foot-bot gripper actuator;
4. restored functionality in 2d dynamics engine (needs cleanup to be more general and easier to add to new robots)
5. fixed foot-bot gripper rendering