FlightGear - Flight Simulator FGAddon

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. :(

Increased compatibility Rembrandt. Update for FG 3.x. Retouching FDM

Retouching FDM. Adding a numbering system for formation flying