Add win_msg module (#22008)

* new implementation of win_msg.  TODO tests

* added check_mode.  Get-AnsibleParam for parameters.  Default msg is now 'Hello world!'. Use hash for $results.
Re-ordered some parameters alphabetically.
Documentation now in raw strings.  Removed spurious required: false.  Added metadata.

* Keep pep8 checks happy

* Really keep pep8 checks happy this time

* update Changelog.md

* make bracket style internally consistent

* added units to display_seconds description

lib/ansible/modules/windows/win_msg.ps1

@@ -0,0 +1,63 @@
+#!powershell
+# This file is part of Ansible
+#
+# Copyright 2016, Jon Hawkesworth (@jhawkesworth) <figs@unity.demon.co.uk>
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible 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
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# WANT_JSON
+# POWERSHELL_COMMON
+
+$stopwatch = [system.diagnostics.stopwatch]::startNew()
+
+$params = Parse-Args $args -supports_check_mode $true
+$check_mode = Get-AnsibleParam -obj $params -name "_ansible_check_mode" -type "bool" -default $false
+
+$display_seconds = Get-AnsibleParam -obj $params -name display_seconds -default "10" -failifempty $False -resultobj $result
+$msg = Get-AnsibleParam -obj $params -name msg -default "Hello world!" -resultobj $result
+$to = Get-AnsibleParam -obj $params -name to -default "*" -failifempty $False -resultobj $result
+$wait = Get-AnsibleParam -obj $params -name wait -default $False -failifempty $False -resultobj $result
+
+$result = @{
+    changed = $false
+}
+
+
+$msg_args = @($to, "/TIME:$display_seconds")
+
+If ($wait) {
+  $msg_args += "/W"
+}
+
+$msg_args += $msg
+if (-not $check_mode) {
+  $ret = & msg.exe $msg_args 2>&1
+  $result.rc = $LASTEXITCODE
+}
+
+$endsend_at = Get-Date| Out-String
+$stopwatch.Stop()
+
+$result.changed = $True
+$result.display_seconds = $display_seconds
+$result.msg = $msg
+$result.runtime_seconds = $stopwatch.Elapsed.TotalSeconds
+$result.sent_localtime = $endsend_at.Trim()
+$result.wait = $wait
+
+If (-not $result.rc -eq 0 ) {
+    Fail-Json $result "$ret"
+}
+  
+Exit-Json $result