LICENSE: correct incorrect claims on *GPL incompatibility

There are currently no statements from any person qualified in the art
of law about the LGPL compatibility of the libfaac license and others.
Furthermore their is no consensus about their compatibility amongth
people not qualified in the art.

Also of interrest may be that ubuntu distributes and links libfaac
to LGPL code. And the ubuntu technical comittee decision about libfaac
https://lists.ubuntu.com/archives/technical-board/2011-February/000703.html

Comments and other viewpoints, especially if i have missed something
are very welcome!

Reviewed-by: Michael Bradshaw <mbradshaw@sorensonmedia.com>
Reviewed-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

LICENSE

@@ -71,8 +71,11 @@ license version needs to be upgraded by passing --enable-version3 to configure.
 incompatible libraries
 ----------------------
 
-The Fraunhofer AAC library, FAAC and aacplus are under licenses incompatible
-with all (L)GPL versions. Thus, unfortunately, since both licenses cannot be
-satisfied simultaneously, binaries resulting from the combination of FFmpeg
-with these libraries are nonfree und unredistributable. If you wish to enable
-any of these libraries nonetheless, pass --enable-nonfree to configure.
+The Fraunhofer AAC library, FAAC and aacplus are under licenses which
+are incompatible with the GPLv2 and v3. We do not know for certain if their
+licenses are compatible with the LGPL.
+If you wish to enable these libraries, pass --enable-nonfree to configure.
+But note that if you enable any of these libraries the resulting binary will
+be under a complex license mix that is more restrictive than the LGPL and that
+may result in additional obligations. It is possible that these
+restrictions cause the resulting binary to be unredistributeable.