2013-09-16: added mercurial guix package

added mercurial guix package

diff --git a/examples/mercurial.w b/examples/mercurial.w
new file mode 100644
--- /dev/null
+++ b/examples/mercurial.w
@@ -0,0 +1,54 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
+;;; Copyright © 2013 Cyril Roelandt <tipecaml@gmail.com>
+;;; Copyright © 2013 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+define-module : mercurial
+  . #:use-module : (guix licenses) #:select : asl2.0 gpl1+ gpl2+ gpl3+
+  . #:use-module : guix packages
+  . #:use-module : guix download
+  . #:use-module : guix build-system gnu
+  . #:use-module : guix build-system python
+  . #:use-module : guix build utils
+  . #:use-module : gnu packages libapr
+  . #:use-module : gnu packages python
+  . #:use-module : gnu packages system
+  . #:use-module : gnu packages emacs
+  . #:use-module : gnu packages compression
+
+define-public hg
+  package
+    name "mercurial"
+    version "2.7.1"
+    source
+      origin
+        method url-fetch
+        uri
+          string-append "http://mercurial.selenic.com/release/mercurial-" 
+              . version ".tar.gz"
+        sha256
+          base32
+            . "121m8f7vmipmdg00cnzdz2rjkgydh28mwfirqkrbs5fv089vywl4"
+    build-system python-build-system
+    home-page "http://mercurial.selenic.com"
+    synopsis "Decentralized version control system"
+    description
+      . "Mercurial is a free, distributed source control management tool. 
+It efficiently handles projects of any size 
+and offers an easy and intuitive interface."
+    license gpl2+