Split Common folder based on operating system families

This change will split common folder to four different folders:
Linux, Unix, Windows and MacOS. Each of these folders includes scripts
which are common for their operating system familes

Task-number: QTQAINFRA-1451
Change-Id: I0668885da43222663a54521ce85653da697425be
Reviewed-by: Heikki Halmet <heikki.halmet@qt.io>

coin/provisioning/common/windows/install-ruby.ps1

@@ -0,0 +1,60 @@
+############################################################################
+##
+## Copyright (C) 2017 The Qt Company Ltd.
+## Contact: http://www.qt.io/licensing/
+##
+## This file is part of the provisioning scripts of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:LGPL21$
+## Commercial License Usage
+## Licensees holding valid commercial Qt licenses may use this file in
+## accordance with the commercial license agreement provided with the
+## Software or, alternatively, in accordance with the terms contained in
+## a written agreement between you and The Qt Company. For licensing terms
+## and conditions see http://www.qt.io/terms-conditions. For further
+## information use the contact form at http://www.qt.io/contact-us.
+##
+## GNU Lesser General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU Lesser
+## General Public License version 2.1 or version 3 as published by the Free
+## Software Foundation and appearing in the file LICENSE.LGPLv21 and
+## LICENSE.LGPLv3 included in the packaging of this file. Please review the
+## following information to ensure the GNU Lesser General Public License
+## requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+## http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+##
+## As a special exception, The Qt Company gives you certain additional
+## rights. These rights are described in The Qt Company LGPL Exception
+## version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+. "$PSScriptRoot\helpers.ps1"
+
+# This script will install Ruby
+
+$version = "2.2.6"
+if( (is64bitWinHost) -eq 1 ) {
+    $arch = "-x64"
+    $sha1 = "4D0E366F0264CDED174E5842B2435E22B81FB57A"
+}
+else {
+    $arch = ""
+    $sha1 = "8649309fffe9c746ad5549d3f7b70490806e95df"
+}
+$url_cache = "\\ci-files01-hki.intra.qt.io\provisioning\windows\rubyinstaller-" + $version + $arch + ".exe"
+$url_official = "https://bintray.com/oneclick/rubyinstaller/download_file?file_path=rubyinstaller-" + $version + $arch + ".exe"
+$rubyPackage = "C:\Windows\Temp\rubyinstaller-$version.exe"
+
+Download $url_official $url_cache $rubyPackage
+Verify-Checksum $rubyPackage $sha1
+cmd /c "$rubyPackage /silent"
+
+echo "Cleaning $rubyPackage.."
+Remove-Item -Recurse -Force "$rubyPackage"
+
+Add-Path "C:\Ruby22-x64\bin"
+
+echo "Ruby = $version" >> ~\versions.txt