Standardize package names: lower-case, not Mixed_CASE (#2475)

* Rename packages

* Upcasing depends_on() in packages.

* Downcased extends('r')

* Fixed erroneously changed URL that had slipped through.

* Fixed typo

* Fixed link from documentation into package source code.

* Fixed another doc problem.

* Changed underscores to dashes in package names.

* Added test to enforce lowercase, no-underscore naming convention.

* Fix r-xgboost

* Downcase more instances of 'R' in package auto-creation.

* Fix test.

* Converted unit test packages to use dashes not underscores

* Downcase `r` in the docs.

* Update module_file_support.rst

Fix r->R for class R.

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

@@ -0,0 +1,44 @@
+##############################################################################
+# 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 Libnbc(Package):
+    """LibNBC is a prototypic implementation of a nonblocking
+    interface for MPI collective operations. Based on ANSI C and
+    MPI-1, it supports all MPI-1 collective operations in a
+    nonblocking manner. LibNBC is distributed under the BSD license.
+    """
+    homepage = "http://unixer.de/research/nbcoll/libnbc/"
+    url      = "http://unixer.de/research/nbcoll/libnbc/libNBC-1.1.1.tar.gz"
+
+    version('1.1.1', 'ece5c94992591a9fa934a90e5dbe50ce')
+
+    depends_on("mpi")
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" % prefix)
+        make()
+        make("install")