Added a command to run 'restart' from another process group.

This allows the service to restart itself.
If we use the regular "restart" command, Windows Service Control
Manager will make sure to kill the entire process group (including
the "winsw.exe restart" itself), preventing the service from getting
restarted.

Main.cs

@@ -49,8 +49,8 @@ namespace winsw
 
         [DllImport("kernel32.dll", SetLastError = true)]
         static extern bool CreateProcess(string lpApplicationName,
-           string lpCommandLine, ref IntPtr lpProcessAttributes,
-           ref IntPtr lpThreadAttributes, bool bInheritHandles,
+           string lpCommandLine, IntPtr lpProcessAttributes,
+           IntPtr lpThreadAttributes, bool bInheritHandles,
            uint dwCreationFlags, IntPtr lpEnvironment, string lpCurrentDirectory,
            [In] ref STARTUPINFO lpStartupInfo,
            out PROCESS_INFORMATION lpProcessInformation);
@@ -641,16 +641,8 @@ namespace winsw
                     if (s == null) ThrowNoSuchService();
                     s.StopService();
                 }
-                if (args[0] == "restart" || args[0]=="restart-self")
+                if (args[0] == "restart")
                 {
-                    if (args[0] == "restart-self")
-                    {
-                        Console.CancelKeyPress += delegate(object sender, ConsoleCancelEventArgs ev)
-                        {
-                            ev.Cancel = true;
-                        };
-                    }
-
                     if (s == null) 
                         ThrowNoSuchService();
 
@@ -665,17 +657,19 @@ namespace winsw
 
                     s.StartService();
                 }
-                /*
-                if (args[0] == "restart-self")
+                if (args[0] == "restart!")
                 {
-                    ProcessStartInfo ps = new ProcessStartInfo();
-                    ps.FileName = d.ExecutablePath;
-                    ps.Arguments = "restart";
-                    ps.UseShellExecute = true;
+                    // run restart from another process group. see README.md for why this is useful.
 
-                    Process.Start(ps);
+                    STARTUPINFO si = new STARTUPINFO();
+                    PROCESS_INFORMATION pi = new PROCESS_INFORMATION();
+
+                    bool result = CreateProcess(null, d.ExecutablePath+" restart", IntPtr.Zero, IntPtr.Zero, false, 0x200/*CREATE_NEW_PROCESS_GROUP*/, IntPtr.Zero, null, ref si, out pi);
+                    if (!result)
+                    {
+                        throw new Exception("Failed to invoke restart: "+Marshal.GetLastWin32Error());
+                    }
                 }
-                */
                 if (args[0] == "status")
                 {
                     if (s == null)