Bug#780719: unblock: flightgear/3.0.0-5

["Rebecca N. Palmer" <rebecca_palmer@zoho.com>]

Symlinks are followed, but I don't think Nasal can create symlinks (and 
if it could, I agree we'd have a bigger problem).

> I'm assuming that there's no good reason for anyone ever to be running flightgear in a privileged context
Agreed: that's one reason I have a 'create an unprivileged user' hook in 
my pbuilder setup.

> I'm also assuming
> that /tmp is the only one where it's likely that other users would be
> able to create such symlinks.
Standard layout is FG_HOME = ~/.fgfs, FG_ROOT = 
/usr/share/games/flightgear and FG_AIRCRAFT (which is a list, not a 
single directory) empty.

Upstream discussion: 
http://sourceforge.net/p/flightgear/mailman/message/33619992/