Adding QWT package. (#4911)

* Adding QWT package.

* Using builtin file filtering.

* Formatting.

var/spack/repos/builtin/packages/qwt/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 NOTICE and LICENSE files 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 Qwt(Package):
+    """The Qwt library contains GUI Components and utility classes which are
+    primarily useful for programs with a technical background. Beside a
+    framework for 2D plots it provides scales, sliders, dials, compasses,
+    thermometers, wheels and knobs to control or display values, arrays, or
+    ranges of type double.
+    """
+    homepage = "http://qwt.sourceforge.net/"
+    url      = "https://downloads.sourceforge.net/project/qwt/qwt/5.2.2/qwt-5.2.2.tar.bz2"
+
+    version('5.2.2', '70d77e4008a6cc86763737f0f24726ca')
+
+    depends_on("qt")
+
+    def install(self, spec, prefix):
+
+        # Subvert hardcoded prefix
+        filter_file(r'/usr/local/qwt-\$\$VERSION', prefix, 'qwtconfig.pri')
+
+        qmake = which('qmake')
+        qmake()
+        make()
+        make("install")