Avionics Instruements Demo

代码说明：

The code is re-coded by myself for modifying the mathematics rotatioin and translation portion of the orginal source from code.google.com with GDI+ matrix operations. The demo program shows how to use these avionics instruments, but lacking of remark/descriptions in the source code due to rush work. Another points for the modifications are: the unit of rotation has been changed to degree, not radian; properties of each customized control are added for using in design phase.