Add package for unison

Add package for unison (the file synchronizer).

Needs the ocaml compiler to build.

var/spack/repos/builtin/packages/unison/package.py

@@ -0,0 +1,50 @@
+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the LICENSE file for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program 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 terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
+from spack import *
+
+
+class Unison(Package):
+    """Unison is a file-synchronization tool for OSX, Unix, and
+       Windows. It allows two replicas of a collection of files and
+       directories to be stored on different hosts (or different disks
+       on the same host), modified separately, and then brought up to
+       date by propagating the changes in each replica to the
+       other."""
+
+    homepage = "https://www.cis.upenn.edu/~bcpierce/unison/"
+    url      = "https://www.seas.upenn.edu/~bcpierce/unison//download/releases/stable/unison-2.48.3.tar.gz"
+
+    version('2.48.4', '5334b78c7e68169df7de95f4c6c4b60f')
+
+    depends_on('ocaml', type='build')
+
+    parallel = False
+    def install(self, spec, prefix):
+        make('./mkProjectInfo')
+        make('UISTYLE=text')
+
+        mkdirp(prefix.bin)
+        install('unison', prefix.bin)
+        set_executable(join_path(prefix.bin, 'unison'))