Added stuff modified from my Hand camera HK 101B add-on
for the FlightGear Flight simulator.

Added
- Copyright notice.
- Licence text of the GNU General Publice Licence,
  version 2 (GPLv2).
- Add-on metadata XML file.
- Nasal script module.
- Configuration XML file.
- Menubar configuration XML file.
- Settings dialog XML file.
- About dialog XML file.

Signed-off-by: Johan G <view.o.matic@gmail.com>