FlightGear - Flight Simulator FGAddon

Added mono sound files for the 717 which should have been committed at r714.

Stereo sound file bug fixes for the 747-400.

This follows from http://thread.gmane.org/gmane.games.flightgear.devel/77932.
With the introduction of the 3D sound engine, all sound files in FlightGear now
must be mono point sources.

The following sound files have been converted directly to mono, by extracting
the left channel and overwriting the original file, as both stereo channels
contain identical information:
- FastenSeatbelt.wav

Stereo sound file bug fixes for the 717 aircraft.

This follows from http://thread.gmane.org/gmane.games.flightgear.devel/77932.
With the introduction of the 3D sound engine, all sound files in FlightGear now
must be mono point sources.

The following original sound files have been preserved by renaming to
*-stereo.wav, as the information content in both stereo channels are similar but
non-identical, and mono versions created by extracting the left channel:
cabinalert.wav, flaps.wav.

The following sound files have been converted directly to mono, by extracting
the left channel and overwriting the original file, as both stereo channels
contain identical information:
touchdown.wav.

mosquito: converted stereo to mono audio file.

spitfireIX: delete obsolete files

Citation II:

removed conditional on cockpit shadow effect - didn't work anyway

New liverie by Enrico CASTALDI. Thanks to him

Adding a colored smoke system with a commands box

Adding a colored smoke system with a commands box

Citation II:

Disabled ALS thrust/flame effect for 3.6 feature freeze. I don't have the time
to finish it in time. :(