licenses: Add 'psfl'.

* guix/licenses.scm (psfl): New variable.

guix/licenses.scm

@@ -1,7 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2013 Andreas Enge <andreas@enge.fr>
-;;; Copyright © 2012 Nikita Karetnikov <nikita@karetnikov.org>
+;;; Copyright © 2012, 2013 Nikita Karetnikov <nikita@karetnikov.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -34,7 +34,7 @@
             lgpl2.0 lgpl2.0+ lgpl2.1 lgpl2.1+ lgpl3 lgpl3+
             mpl2.0
             openldap2.8 openssl
-            public-domain
+            psfl public-domain
             x11
             zlib))
 
@@ -196,6 +196,11 @@ which may be a file:// URI pointing the package's tree."
            "https://www.gnu.org/licenses/license-list#newOpenLDAP"))
               ;; lists OpenLDAPv2.7, which is virtually identical
 
+(define psfl
+  (license "Python Software Foundation License"
+           "http://docs.python.org/license.html"
+           #f))
+
 (define public-domain
   (license "Public Domain"
            "http://directory.fsf.org/wiki/License:PublicDomain"