Add a package: dmlc/mxnet. (#3579)

* Add dmlc/mxnet packags.

* Build mxnet+cuda+opencv with GCC-4.8.5 and GCC-5.4.0.

* Build mxnet version 0.10.0, 0.10.0.post1 and 0.10.0.post2.

* Add component version constrain for mxnet 0.10.0.x .

* Go through flake8.

* Replace commit hash with commit date as package version.

* Go throught Travis-CI.

* Update submodule version for 0.10.0.post2.

* Add openmp variant for dmlc-core and mxnet.

* Refine variant handling.

* Fix filter_file for dmlc-core.

* Cut long strings into multiple lies due to PEP8 requirements.

* Fix for PEP8.

* Add CUB_INCLUDE.

* Add py-mxnet: Python binding for MXNet.

* Remove distutils.dir_util.

* Add the profiler variant for mxnet.

* Add a shared variant for nnvm.

* Set USE_OPENMP to OFF by default.

* Fix flake8 errors.

* Fix flake8 issues.

* flake8 issues again.

var/spack/repos/builtin/packages/dmlc-core/cmake.patch

@@ -0,0 +1,21 @@
+From 82f2bde92e1f1bf35bdf7b93cacb0aa72d9f096b Mon Sep 17 00:00:00 2001
+From: Jianwen WEI <weijianwen@gmail.com>
+Date: Fri, 18 Aug 2017 23:16:05 +0800
+Subject: [PATCH] Patch CMakeLists.txt to install make/ dir into destination.
+
+---
+ CMakeLists.txt | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index f038dcb..ed01b82 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -134,6 +134,7 @@ endif()
+ install(TARGETS dmlc ARCHIVE DESTINATION lib LIBRARY DESTINATION lib) 
+ install(DIRECTORY include DESTINATION .)
+ install(DIRECTORY doc DESTINATION .)
++install(DIRECTORY make DESTINATION .)
+ 
+ # ---[ Linter target
+ if(MSVC)

var/spack/repos/builtin/packages/dmlc-core/package.py

@@ -0,0 +1,57 @@
+##############################################################################
+# 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 DmlcCore(CMakePackage):
+    """DMLC-Core is the backbone library to support all DMLC projects,
+    offers the bricks to build efficient and scalable
+    distributed machine learning libraries."""
+
+    homepage = "https://github.com/dmlc/dmlc-core"
+    url      = "https://github.com/dmlc/dmlc-core.git"
+
+    version('master', git='https://github.com/dmlc/dmlc-core.git')
+    version('20170508', git='https://github.com/dmlc/dmlc-core.git',
+    commit='a6c5701219e635fea808d264aefc5b03c3aec314')
+
+    variant('openmp', default=False, description='Enable OpenMP support')
+
+    patch('cmake.patch')
+
+    def patch(self):
+        filter_file('export CC = gcc', '', 'make/config.mk', string=True)
+        filter_file('export CXX = g++', '', 'make/config.mk', string=True)
+        filter_file('export MPICXX = mpicxx', '',
+                    'make/config.mk', string=True)
+        filter_file(r'^USE_OPENMP\s*=.*',
+                    'USE_OPENMP=%s' % ('1' if '+openmp' in self.spec else '0'),
+                    'make/config.mk')
+
+    def cmake_args(self):
+        spec = self.spec
+        return [
+            '-DUSE_OPENMP=%s' % ('ON' if '+openmp' in spec else 'OFF'),
+        ]