Fix LICENSE to remove obsolete references to the QPL.

At the same time, remove the linking exception for the Generator.
Also, mention that the files in test/ are not covered by any license.

LICENSE

@@ -5,19 +5,14 @@ In the following, "THE LIBRARY" refers to the following files:
   2- the OCaml source files whose basename appears in the file
      src/menhirLib.mlpack and whose extension is ".ml" or ".mli".
 
-"THE GENERATOR" refers to all other files in this archive.
-
-THE LIBRARY is distributed under the terms of the GNU Library General
-Public License version 2 (included below).
+"THE GENERATOR" refers to all other files in this archive or repository,
+except those in the subdirectory test/, which are not covered by this license.
 
 THE GENERATOR is distributed under the terms of the GNU General Public
 License version 2 (included below).
 
-As a special exception to the Q Public Licence, you may develop
-application programs, reusable components and other software items
-that link with the original or modified versions of the Generator
-and are not made available to the general public, without any of the
-additional requirements listed in clause 6c of the Q Public licence.
+THE LIBRARY is distributed under the terms of the GNU Library General
+Public License version 2 (included below).
 
 As a special exception to the GNU Library General Public License, you
 may link, statically or dynamically, a "work that uses the Library"