this way, keyboard buttons can work the same way as joystick buttons
- added declaration for FGBinding::fire(double); this adds a setting
property to the arguments passed to the command, so that it can use
the current axis position as part of its calculations
- added data structures from joystick.cxx
Fixed a few glitches in the autopilot keys
Added a #define to be able to make a compile time decision to revert to
older GPS like autopiolt behavior this define SHOULD become a property
so that it is run time switchable.
