Add license information for Fluid (R3) Soundfont

We ship these files at least with our Windows installer so they should
be part of the license information.

LICENSE.txt

@@ -639,6 +639,33 @@ THE SOFTWARE.
 Uses OpenSSL which is available from https://www.openssl.org under the
 Apache License 2.0 
 
+-------------------------------------------------------------------------------
+
+Uses Fluid (R3) Soundfont which is available under the following terms:
+
+Copyright (c) 2000-2002, 2008 Frank Wen <getfrank@gmail.com>
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
 -------------------------------------------------------------------------------
 
  GNU LESSER GENERAL PUBLIC LICENSE