Problem: unity license not mentioned in debian/copyright

Solution: add it

packaging/debian/copyright

@@ -44,6 +44,29 @@ Copyright: 2009-2011, 250bpm s.r.o
  2007-2011, Other contributors as noted in the AUTHORS file
 License: LGPL-3.0+
 
+Files: external/unity/*
+Copyright: 2007-2014 Mike Karlesky
+           2007-2014 Mark VanderVoord
+           2007-2014 Greg Williams
+License: MIT
+ 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.
+
 Files: debian/*
 Copyright: 2014-    , Laszlo Boszormenyi (GCS) <gcs@debian.org>
  2012-2014, Alessandro Ghedini <ghedo@debian.org>