The new script is documented in the flightgear wiki (see "bash completion") and adds functionality such as advanced detection of FG_ROOT and other paths, and many completions not available before.
The list of possible command line options is automatically generated from "fgfs --help --verbose".
The author of the original script (mfranz) has agreed to replace this script.
dirs is only fast enough with hot file-cache, but a bit too painful
otherwise. Updating the aircraft.list is now easier, though: Just
type $ fgfs --aircraft=?<TAB>
