[pkg-fgfs-crew] flightgear 3.4.1

[Rebecca N. Palmer]

Upstream plan to release 3.4.1 "this week": 
http://sourceforge.net/p/flightgear/mailman/message/33683511/

This will include the #780712 and #780716 security fixes, which need to 
get into Ubuntu 15.04 (which closes for bug fixes on 16 Apr: 
https://wiki.ubuntu.com/VividVervet/ReleaseSchedule , 
https://wiki.ubuntu.com/FreezeExceptionProcess#FeatureFreeze_for_bugfix-only_updates 
).

The libsimgear*3.4.0 -> libsimgear*3.4.1 soname bump is real this time, 
due to efbca9427485c4aa4a38591bfe44c1571cfd82f4.  Ubuntu have previously 
accepted those under freeze (LP#1425366), but I do not know whether they 
will do so this late; the alternative is to make our own half-.0-half-.1 
omitting this fix.

It does not include the "disable /tmp/*.xml writing" fix for #780867; if 
you decide to include that as a Debian patch, note that you need to 
remove it from _both_ flightgear src/Main/util.cxx and flightgear-data 
Nasal/IOrules.  (3.5 moves all the security into flightgear, but 3.4.1 
only moves as much as actually needed to be moved.)

I do not recommend enabling the launcher (as in current Alioth) at this 
point: upstream intended it to be Mac-only for 3.4 
(0b79f7a31652284edf0bfb64734bc52b66426b05) and it has multiple issues on 
Linux, http://sourceforge.net/p/flightgear/mailman/message/33679374/