Updating licensing

Related to issue #473

LICENSE.txt

@@ -3,11 +3,14 @@ All rights reserved.
 
 The general priciple of the licensing is as follows. Everything that's
 needed to run/build/install/link the system is MIT licensed. This allows
-easy distribution and running of the system everywhere. Everything else that's
-not needed to run/build/install/link is usually GPLv2 licensed.
-
-Everything relevant should have a license at the top. There should be no
-ambiguities. However, in case there are any, please contact the author.
+easy distribution and running of the system everywhere. Files that
+have no copyright header are also MIT licensed.
+
+Everything else that's not needed to run/build/install/link is usually GPLv2
+licensed or compatible (see the copyright headers.) The only exceptions are the
+following files in docs/:
+* `splncs03.bat` which is under the LPPL
+* `ieee.cls` which is covered by the IEEE Copyright Policy
 
 
 MIT License